RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: The population of a bacteria colony doubles every day. If it was started 7 days ago with 2 bacteria and each bacteria lives for 12 days, how large is the colony today?
A.512
B.768
C.256
D.2048
Answer: C.256
Explanation: 7 days ago- 2
6 days ago- 4
5 days ago- 8
4 days ago- 16
3 days ago- 32
2 days ago- 64
Yesterday- 128
Today- 256
Ans:C
Question: From the below series find the remainder? 1201×1203×1205×1207 is divided by 6?
A.3
B.4
C.6
D.7
Answer: A.3
Explanation: If you don't know the above rule, this problem is really calculation intensive.
But by applying the above rule, when 1201, 1201, 1203, 1204 divided by 6, leaves remainders 1, 3, 5, 1. The product of these remainders = 15.
When 15 is divided by 6, Remainder is 3
A
Question: A shepherd had 17 sheep. All but nine died. How many was he left with ?
A.Nil
B.8
C.9
D.10
Answer: C.9
Explanation: all but nine died means all except nine died..
ANSWER:C
Question: If the probability Q of rain on any given day in city x is 50% what is the probability it with rain on exactly 3 days in a five day period?
A.8/125
B.2/25
C.5/16
D.8/25
Answer: C.5/16
Explanation: 5C3 (1/2)^3(1/2)^2
= (5 * 4 * 3!)/2!3! * 1/32
Q= 5/16
Answer - C
Question: A coin is tossed live times. What is the probability that there is at the least one tail?
A.31/32
B.31/36
C.31/30
D.31/32
Answer: A.31/32
Explanation: Let P(T) be the probability of getting least one tail when the coin is tossed five times.
= There is not even a single tail.
i.e. all the outcomes are heads.
= 1/32 ; P(T)
= 1 - 1/32
= 31/32
Answer: A
Question: A three-character password consists of one letter of the alphabet and two different digits between 0 and 9, inclusive. The letter must appear as the second or third character of the password. How many different passwords are possible?
A.4,680
B.18,720
C.26,000
D.37,440
Answer: A.4,680
Explanation: 4 character password: DLD
First digit can be chosen in 10 ways.
The letter can be chosen in 26 ways.
Next digit can be chosen in 9 ways.
This gives us 10*26*9 ways
Now, the letter can also be DDLD so there will be another 10*9*26 ways
Total = 10*26*9*2 = 4,680 ways
A
Question: A man can row upstream at 4km/hr and down stream at 11km/hr find mans rate in still water ?
A.4.5km/hr
B.5.5km/hr
C.7.5km/hr
D.6.5km/hr
Answer: C.7.5km/hr
Explanation: given upstream(u) =4km/hr
down stream (v)= 11km/hr rate in still water =1/2(u+v)=1/2(4+11)=7.5km/hr Answer is (C):7.5
Question: A family consists of two grandparents, two parents and three grandchildren. The average age of the grandparents is 65 years, that of the parents is 45 years and that of the grandchildren is 8 years. What is the average age of family?
A.6/7years
B.B)31
C.C)30
D.D)33
Answer: A.6/7years
Explanation: Required average
= (65 x 2 + 45 x 2 + 8 x 3 )/(2 + 2 + 3)
= (130 + 90 + 24)/7
=244/7
= 34 6/7years.
Answer is A
Question: The present ages of three persons are in proportions 4:7:9 Eight years ago ,the sum of their ages was 56.Find their present ages (in years)
A.8,20,28
B.16,28,36
C.20,35,45
D.None of these
Answer: B.16,28,36
Explanation: Solution
Let their present ages be 4x,7x and 9x years respectively.
Then,(4x-8)+(7x -8)+ (9x-8)=56 ⇔ 20x =80 ⇔ x=4.
∴ Their present ages are 16 years ,28 years and 36 year respectively. Answer B
Question: What is the remainder if 7^4 is divided by 100?
A.5
B.4
C.1
D.2
Answer: C.1
Explanation: 7*7*7*7/100=2401/100=24 reminder 1
Answer : C
Question: There are two concentric circles with radii 8 and 6. If the radius of the outer circle is increased by 25% and the radius of the inner circle decreased by 50%, by what percent does the area between the circles increase?
A.225
B.250
C.275
D.300
Answer: A.225
Explanation: The area of a circle is piR^2, where R is the radius.
The area of the big circle is 64pi.
The area of the small circle is 36pi.
The area A1 between the circles is 28pi.
When the big circle's radius increases, the new area is 100pi.
When the small circle's radius decreases, the new area is 9pi.
The area A2 between the circles is 91pi.
The ratio of A2/A1 is 91/28 = 3.25 which is an increase of 225%.
The answer is A.
Question: By selling an article at Rs.600, a profit of 25% is made. Find its cost price?
A.Rs.488
B.Rs.428
C.Rs.299
D.Rs.480
Answer: D.Rs.480
Explanation: SP = 600
CP = (SP)*[100/(100+P)]
= 600 * [100/(100+25)]
= 600 * [100/125] = Rs.480
Answer: D
Question: A garrison has provisions for 90 soldiers for 160 days. After 100 days 45 more soldiers will join the group. For how many more days will the provisions last?
A.15 days
B.30 days
C.35 days
D.none of the above
Answer: D.none of the above
Explanation: Explanation :
Actually after 100 days,
If 90 members are there, provisions come for 60 more days (since total 160 days)
But now 135 members are there.
So number of days = (90/135) X 60 = 20 days.
Answer : D
Question: Three faces of a fair die are Yellow, two faces red and one blue.The die is tossed three
times. The probability that the colours, yellow, red and blue appear in the first, second and
third tosses respectively is
A.1/36
B.1/18
C.1/32
D.1/37
Answer: A.1/36
Explanation: Probability of getting yellow color = P(Y) = 3/6 = 1/2
Probability of getting red color = P(R) = 2/6 = 1/3
Probability of getting blue color = P(B) = 1/6
So, the probability that the colors yellow, red and blue appear in first, second and third toss respectively= P(Y ∩ R ∩ B) = P(Y) x P(R) x P(B) = 1/2 x 1/3 x 1/6 = 1/36
ANSWER:A
Question: A reduction of 20% in the price of salt enables a lady to obtain 10kgs more for Rs.100, find the original price per kg?
A.Rs.2.9
B.Rs.2.1
C.Rs.2.5
D.Rs.2.2
Answer: C.Rs.2.5
Explanation: Explanation:
100*(20/100) = 20 --- 10
? --- 1 => Rs.2
100 --- 80
? --- 2 => Rs.2.5
Answer: C
Question: A certain lab experiments with white and brown mice only. In one experiment, 3/7 of the mice are white. If therare24 brown mice in the experiment, how many mice in total are in the experiment?
A.14
B.16
C.18
D.12
Answer: C.18
Explanation: Let total number of mice = M
Number of white mice = 3/7 M
Number of brown mice = 4/3 M = 18
=> M = 18
Answer C
Question: A right circular cylinder and a cone are there. Base radius of cone is equal to radius of cylinder. What is the ratio of height to slant side if their volume are the same?
A.1:3
B.3:1
C.1:2
D.2:1
Answer: B.3:1
Explanation: 1/3 pi r^2 h1 = pi r^2 h2
h1/h2= 3/1
height of cone : height of cylinder = 3:1
ANSWER:B
Question: The average salary of all the workers in a workshop is Rs. 8000. The average salary of 7 technicians is Rs. 16000 and the average salary of the rest is Rs. 6000. The total number of workers in the workshop is :
A.22
B.21
C.35
D.37
Answer: C.35
Explanation: Explanation:
Lot the total number of workers be v Then,
8OOOv = (16000 * 7) + 6000 (v - 7) <=> 2000v = 70000 <=> v = 35
Answer: C) 35
Question: A train 280 m long, running with a speed of 72 km/hr will pass a tree in?
A.17 sec
B.16 sec
C.18 sec
D.14 sec
Answer: D.14 sec
Explanation: Speed = 72 * 5/18
= 20 m/sec
Time taken = 280 * 1/20
= 14 sec
Answer: D
Question: The total circumference of two circles is 49. If the first circle has a circumference that is exactly twice the circumference of the second circle, then what is the approximate sum of their two radii?
A.7.8
B.6.0
C.6.7
D.9.7
Answer: A.7.8
Explanation: Let r= Radius of smaller circle. Let R = Radius of larger circle
Therefore:
2πr + 2πR = 49
where 2r = R
Thus:
2πr + 4πr = 49
6πr = 49
r = approx 2.6
πR + 2Rπ = 49
3πR = 49
R = approx 5.2
r + R = approx 7.8
Answer :A
Question: Working alone, Printers X, Y, and Z can do a certain printing job, consisting of a large number of pages, in 12, 30, and 40 hours, respectively. What is the ratio of the time it takes Printer X to do the job, working alone at its rate, to the time it takes Printers Y and Z to do the job, working together at their individual rates?
A. 4/11
B. 1/2
C. 15/22
D. 120/7
Answer: D. 120/7
Explanation: P1 takes 12 hrs
Rate for P2P3 together = 1/30 + 1/40 = 7/120
Therefore they take 120/7
Ratio = 120/7 = D
Question: A total of Y tourists were transported by bus to a certain museum. If there were Z tourists on each bus, which of the following expresses the number of buses used?
A. YZ
B. Y/Z
C. Z/Y
D. Y-Z
Answer: B. Y/Z
Explanation: IMHO (B)Y/Z as well !
Number of buses used = Total number of tourists / Number of tourists per bus => Y/Z
PS : In case of any doubt , plug in some numbers
Total number of tourists transported by bus = 500
Number of tourists per bus = 10
No of buses required = 500/10
Question: A certain airline's fleet consisted of 80 type A planes at the beginning of 1980. At the end of each year, starting with 1980, the airline retired 3 of the TYPE A planes and acquired 4 new type B plans. How many years did it take before the number of type A planes left in the airline's fleet was less than 50 percent of the fleet?
A.9
B.10
C.11
D.12
Answer: D.12
Explanation: Let x be the number of years.
4x > 80 - 3x
7x > 80
x > 11 + 3/7
The answer is D.
Question: 2. Seven movie addicts- Guna, Isha, Leela, Madhu, Rinku, Viji and Yamini attend a film festival. Three films are shown, one directed by Rajkumar Hirani ,one by S.Shankar,and one by Mani Ratnam. Each of the film buffs sees only one of the three films. The films are shown only once, one film at a time. The following restrictions must apply :- Exactly twice as many of the film buffs sees the S.shankar film as see the Rajkumar Hirani film.- Guna and Rinku do not see the same film as each other.- Isha and Madhu do not see same film as each other.- Viji and Yamini see the same film as each other.- Leela sees the S.Shankar film.- Guna sees either the Rajkumar Hirani film or the Mani Ratnam film.Which one of the following could be an accurate matching of the film buffs to films ?(A) Guna: the S.Shankar film; Isha: the Mani Ratnam film; Madhu: the S.Shankar film(B) Guna: the Mani Ratnam film; Isha: the Rajkumar Hirani film; Viji: the Rajkumar Hirani film(C) Isha : the S.Shankar film; Rinku: the Mani Ratnam film; Viji: the Rajkumar Hirani film(D) Madhu: the Mani Ratnam film; Rinku: the Mani Ratnam film; Viji: the Mani Ratnam film
A.A
B.B
C.C
D.D
Answer: B.B
Explanation: Explanation:
Guna × Rinku
Isha × Madhu
(Viji + Yamini)
Leela - Film: Shankar
Guna = RKH/Mani Ratnam
The following options are possible:
RKH	Shankar	Mani Ratnam
1	2	4
2	4	1
We will take options and check them.
Option A: Guna should not watch Shankar's Film. So ruled out
Option B:
RKH	Shankar	Mani Ratnam
Isha	_	Guna
Viji	_	_
Now Yamini also watch RKH. Which is not possible.
Option C:
RKH	Shankar	Mani Ratnam
Viji	Isha	Rinku
Yamini	Leela	_
As Guna should not be watching Shankar's movie she should watch Mani ratnam's which is not possible.
Option D:
RKH	Shankar	Mani Ratnam
Guna	Leela	Madhu
_	Isha	Rinku
_	_	Viji and Yamini
Answer:B
Question: If xy is an integer, which of the following must also be an integer?
I. x/y
II. x
III. y/x
A.I alone
B.II alone
C.I and II
D.I and III
Answer: B.II alone
Explanation: Lets take X = 3 and Y = 7
Then XY = 21 which is an integer.
But X/Y = 3/7 --> Not an integer.
Y/X = 7/3 --> Not an integer.
X alone is 3. which is an integer.
Hence B.
Question: A train covers a distance in 50 min, if it runs at a speed of 48kmph on an average. The speed at which the train must run to reduce the time of journey to 40min will be
A.45 min
B.60 min
C.55 min
D.70 min
Answer: B.60 min
Explanation: Time = 50/60 hr = 5/6hr
Speed = 48mph
distance = S*T = 48 * 5/6 = 40km
time = 40/60hr = 2/3hr
New speed = 40* 3/2 kmph = 60kmph
Answer : B.
Question: If 7 men and 2 boys working together, can do four times as much work per hour as a man and a boy together. Find the ratio of the work done by a man and that of a boy for a given time?
A.3:2
B.2:3
C.3:3
D.1:2
Answer: B.2:3
Explanation: B
2:3
7M + 2B = 4(1M + 1B)
7M + 2B = 4M + 4B
3M = 2B
The required ratio of work done by a man and a boy = 2:3
Question: The speed of a boat in still water is 55kmph and the speed of the current is 20kmph. Find the speed downstream and upstream?
A.kmph
B.kmph
C.kmph
D.kmph
Answer: B.kmph
Explanation: Speed downstream = 55 + 20 =75 kmph
Speed upstream = 55 - 20 = 35 kmph
Answer:B
Question: A semicircle is drawn with AB as its diameter. From C, a point on AB, a line perpendicular to AB is drawn, meeting the circumference of the semicircle at D. Given that AC=2cm and CD=6cm, the area of the semicircle in square cm will be ?
A.30pi
B.40pi
C.50pi
D.60pi
Answer: C.50pi
Explanation: let O be center of circle and radius be x.
C can be anywhere on AB.Let us suppose that C is somewhere between A and O.
AC=2cm....so CO=(x-2)
DO=x,CD=6cm
CDO form a right angled triangle with right angle at C.
Using Pythagoras theorem,
x^2=6^2+(x-2)^2
4x=40
x=10cm
area=[pi(x)^2]/2
area=50pi
ANSWER:C
Question: In how many ways a committee consisting of 5 men and 6 women can be formed from 8 men and 10 women?
A.A)12540
B.B)11450
C.C)11760
D.D)13250
Answer: C.C)11760
Explanation: Required number of ways = 8C5*10C5 = 8C3*10C4 = 11760
Answer is C
Question: Reena took a loan of Rs. 1200 with simple interest for as many years as the rate of interest. If she paid Rs. 768 as interest at the end of the loan period, what was the rate of interest?
A.3.6
B.6
C.8
D.Cannot be determined
Answer: C.8
Explanation: let rate = R% and time = R years
Then ( 1200 x R x R /100) = 768
=> 12R2= 768
=> R2= 64
=> R= 8
Answer C
Question: Looking at a portrait of a man, Harsh said, "His mother is the wife of my father's son. Brothers and sisters I have none." At whose portrait was Harsh looking ?
A.His son
B.His cousin
C.His uncle
D.His nephew
Answer: A.His son
Explanation: Explanation:
Since Harsh has no brother or sister, so he is his father's only son. Now, wife of my father's son — my wife.
So, Harsh's wife is the man's mother or the man is Harsh's son.
Answer: A) His son
Question: The rate of a certain chemical reaction is directly proportional to the concentration of chemical A present and inversely proportional to the concentration of chemical B present. If the concentration of chemical B present is increased by 100 percent, which of the following is closest to the percent change in the the concentration of chemical A required to keep the reaction rate unchanged.
A.100 % decrease
B.60% decrease
C.30% decrease
D.40% increase
Answer: A.100 % decrease
Explanation: Let's say here is the formula of how A and B affects the reaction speed:
rate = A/B
After the concentration B is increased by 100%, the percentage of B
become 2B, to keep 'rate' the same, need to have 2A being doubled.
Which means A increased by 100%.
Answer : A
Question: In a friendship gang Mala has 5 gang, in how many ways can he invite one or more of the gang to his house?
A.31
B.12
C.58
D.74
Answer: A.31
Explanation: mala can select one or more than one of his 8 gang.
=> Required number of ways = 2^5 – 1= 31.
A
Question: A 12 meter long wire is cut into two pieces. If the longer piece is then used to form a perimeter of a square, what is the probability that the area of the square will be more than 4 if the original wire was cut at an arbitrary point?
A.1/6
B.2/3
C.3/10
D.1/3
Answer: B.2/3
Explanation: A square with an area of 4 has a perimeter of 8.
For the area to be >4, the longer piece must be >8.
The wire must be cut within 4 meters from either end.
The probability of this is 8/12 = 2/3.
The answer is B.
Question: A laborer is engaged for 30 days on the condition that he receives Rs.25 for each day he works and is fined Rs.7.50 for each day is absent. He gets Rs.425 in all. For how many days was he absent?
A.22
B.38
C.19
D.10
Answer: D.10
Explanation: Explanation:
30 * 25 = 750
425
-----------
325
25 + 7.50 = 32.5
325/32.5 = 10
Answer:D
Question: In a certain diving competition, 5 judges score each dive on a scale from 1 to 10. The point value of the dive is obtained by dropping the highest score and the lowest score and multiplying the sum of the remaining scores by the degree of difficulty. If a dive with a degree of difficulty of 3.2 received scores of 7.5, 8.1, 9.0, 6.0, and 8.5, what was the point value of the dive?
A.68.8
B.73.6
C.75.2
D.77.12
Answer: D.77.12
Explanation: Degree of difficulty of dive = 3.2
Scores are 6.0 , 7.5 , 8.1 , 8.5 and 9.0
We can drop 6.0 and 9.0
Sum of the remaining scores = (7.5+8.1+8.5)= 24
Point of value of the dive = 24.1*3.2 =77.12
Answer D
Question: (32^32^32)/9 will leave a remainder?????
A.2
B.3
C.4
D.5
Answer: C.4
Explanation: 32^32^32=(2^5)^32^32=2^5120.
2^5120/9
=((2^3)^1706*2^2)/9
=((9-1)^1706*2^2)/9
=(-1)^1706*4
=4
ANSWER:C
Question: The food in a camp lasts for 40 men for 50 days. If ten more men join, how many days will the food last?
A.20days
B.30days
C.40days
D.50days
Answer: C.40days
Explanation: one man can consume the same food in 40*50 = 2000 days.
10 more men join, the total number of men = 50
The number of days the food will last = 2000/50 = 40 days.
Answer: C
Question: There are 8 girls and 8 boys. If they are to be seated in a row, what is the probability that no two girls sit together?
A.A)1/16!
B.B)6!5!/16!
C.C)6!6!/16!
D.D)2∗8!8!/16!
Answer: D.D)2∗8!8!/16!
Explanation: If girls are alternate, then only no 2 girls can be together.
So among 16 places, girls can be seated in 8 alternate places in 8! ways.
And boys can be seated in the remaining 8 places in 8! ways.
Therefore total number of ways = 8! * 8!
But there could be 2 such arrangements-->
1. When first place is filled by a girl
2. When first place is filled by a boy
Therefore total number of ways = 2*8! * 8!
Also total number of ways to fill 16 places = 16!
Hence probability =2∗8!8!/16!
Answer:D
Question: Rajesh can finish 1/6 of his home work in one hour. Seema can finish 3/7 of
her homework in 70 minutes and Ramya can finish 3/4 of her homework in
three and a half hours. If all of them start their home work at 12.00 PM and can
go to play as soon as they all finish their homework. When can they start to
play, if they take a break at 3.30 PM for 30 minutes?
A.4:30pm
B.5:10pm
C.6:30pm
D.5:30pm
Answer: C.6:30pm
Explanation: rajesh can finish his work in 6 hr,
ramya can finish her work in 2.7 hr
seema can finish in 3.5 hr
so 6:30pm they can go to play
ANSWER:C
Question: Out of 7 persons working on a project, 4 are graduates. If 3 are selected, what is the probability that there is at least one graduate among them?
A.A)3/7
B.B)5/4
C.C)5/7
D.D)5/6
Answer: A.A)3/7
Explanation: P(at least one graduate) = 1 - P(no graduates)
= 1 - ⁶C₃/¹⁰C₃
= 1 - (6 * 5 * 4)/(7 * 6 * 5)
= 3/7
Answer:A
Question: A car moves at 102 km/hr. What is the speed of the car in meters per second ?
A.20 2/9m sec
B.28 1/3m sec
C.24 1/9m sec
D.26 2/3m sec
Answer: B.28 1/3m sec
Explanation: Explanation:
Speed=(102∗5/18)m/sec
=85/3 m/sec
=28 1/3msec
Option B
Question: x percent of y percent of z is decreased by y percent. What is the result?
A.(100xyz - xy^2z) / 1000000
B.(xz - y) / 100
C.(xz - y) / 10,000
D.(xyz - 2y) / 100
Answer: A.(100xyz - xy^2z) / 1000000
Explanation: We're told that X percent of Y percent of Z is DECREASED by Y percent. We're asked for the result of all of this math.
IF....
X = 10
Y = 50
Z = 100
First, 50% of 100 = 50
Next, 10% of 50 = 5
Finally, 5 decreased by 50% of itself is 2.5
So we're looking for an answer that equals 2.5 when X=10, Y=50 and Z=100.
Answer A. (100xyz - xy^2z) / 1,000,000 = (5,000,000 - 2,500,000)/1,000,000 = 2,500,000/1,000,000 = 2.5 This is a MATCH
Answer B. (xz - y) / 100 = (1,000 - 50)/100 = 950/100 = 9.5 NOT a match
Answer C. (xz - y) / 10,000 = 950/10,000 = .095 NOT a match
Answer D. (xyz - 2y) / 100 = (50,000 - 100)/100 = 49,900/100 = 499 NOT a match
Answer E. (xyz - 2y) / 10,000 = 49,900/10,000 = 4.99 NOT a match
A
Question: Ram and Krishna start from A and B respectively at the same time and travel towards each other at constant speeds of 30m/m and 40 m/m respectively along the same route. Ram meets Krishna at point C on the road after 10 minutes. Find the total distance between A to B.
A.700 meters
B.1000 meters
C.700 kilometers
D.555 meters
Answer: A.700 meters
Explanation: Vr=30 m/m, Vk= 40m/m;
t-time for Meet.
distance A-C = 30*10=300 m
distance B-C = 40*10=400 m
therefore distance A-C = 300+400=700 m.
option A
Question: A hall 36m long and 15m broad is to be paved with stones, each measuring 4dm by 5 dm. The number of stones required is:
A.180
B.2700
C.18
D.18000
Answer: B.2700
Explanation: Area of the hall= 3600*1500
Area of each stone= (40*50)
Therefore, number of stones= (3600*1500/ 40*50)= 2700
ANSWER:B
Question: The market value of a certain machine decreased by 10 percent of its purchase price each year. If the machine was purchased in 1982 for its market value of $8,000, what was its market value two years later?
A. $8,000
B. $5,600
C. $3,200
D. $6,400
Answer: D. $6,400
Explanation: D
Market value in 1982= $ 8000
Market value in 1983 = $ 8000- ($ 8000 x 10/100) = 8000-800= $ 7200
Market value in 1984 = Market value in 1983 - (10 % of $8000)= 7200-800 = $6400
Question: On her annual road trip to visit her family in Seal Beach, California, Traci stopped to rest after she traveled 1⁄3 of the total distance and again after she traveled 1⁄2 of the distance remaining between her first stop and her destination. She then drove the remaining 100 miles and arrived safely at her destination. What was the total distance, in miles, from Traci’s starting point to Seal Beach?
A. 250
B. 300
C. 350
D. 400
Answer: B. 300
Explanation: Let D = total distance
Traci traveled 1/3 = D/3
i.e. remaining distance = 2D/3
She traveled 1/2 th of 2D/3 = D/3
Thus:
D = (D/3) + (D/3) + 100
D = 300
ANSWER: B
Question: In a mixture of 45 litres the ratio of milk to water is 4:1. Additional 21 litres of water is added to the mixture. Find the ratio of milk to water in the resulting mixture.
A.2/1
B.4/1
C.6/5
D.3/4
Answer: C.6/5
Explanation: Given that Milk/Water=4x/x and 4x+x=45 --> x=9.
Thus Milk=4x=36 liters and Water=x=9 liters.
New ratio = 36/(9+21) = 36/30 = 6/5.
Answer: C.
Question: In how many different number of ways a combination of 3 persons can be selected from 4 men and 2 women?
A.200
B.220
C.240
D.260
Answer: A.200
Explanation: 6C3 × 5C2
6C3
= 6!/(3! . 3!)
= (6 × 5 × 4)/(3 × 2)
= 5 × 4 = 20.
5C2
= 5!/(3! . 2!)
= 5 × 2 = 10
= 20 × 10 = 200.
A)
Question: A trader mixes 26 kg of rice at Rs. 20 per kg with 30 kg of rice of other variety at Rs. 36 per kg and sells the mixture at Rs. 34 per kg. His profit percent is:
A.No profit, no loss
B.5%
C.19%
D.10%
Answer: C.19%
Explanation: Explanation :
C.P. of 56 kg rice = (26 * 20 + 30 * 36) Rs. = (520 + 1080) Rs. = 1600 Rs.
S.P. of 56 kg rice = (56 * 34) Rs. = 1904 Rs.
Profit % = (1904−1600/1600∗100)% = 19%
Answer : C
Question: John invested part of his savings into a investment X that earned a profit of 10% and the rest of the savings into an investment Y that lost 15%. If John neither made a profit nor a loss, then what fraction of his savings was invested in investment X?
A.3/5
B.2/3
C.7/10
D.3/4
Answer: A.3/5
Explanation: X(1+10/100) + Y(1-15/100) = X+Y
this gives 2X = 3Y
or X/Y = 3/2
So, fraction invested in X = 3/5
ANSWER:A
Question: The probabilities of solving a question by 3students A, B & C are 1/2,1/3 &1/4, respectively. The probability that the problem will be solved is?
A.1/3
B.3/4
C.3/5
D.3/7
Answer: B.3/4
Explanation: Sol. First, we find the probability of not solving the problem x PTO x = (1 — D x - D x - D
1 2 3 1 =iXiX71=4;
1 3 Required probability 3/4
B
Question: If a person walks at 14 km/hr instead of 10 km/hr, he would have walked 20 km more. The actual distance traveled by him is?
A.50
B.267
C.26
D.87
Answer: A.50
Explanation: Let the actual distance traveled be x km. Then,
x/10 = (x + 20)/14
4x - 200 =>x = 50 km.
Answer:A
Question: The average age of a class of 39 students is 15 years. If the age of the teacher be included, then the average increases by3 months. Find the age of the teacher.
A.22 Yrs
B.25 Yrs
C.26 Yrs
D.32 Yrs
Answer: B.25 Yrs
Explanation: Sol. Total age of 39 persons = (39 x 15) years
= 585 years.
Average age of 40 persons= 15 yrs 3 months
= 61/4 years.
Total age of 40 persons = (_(61/4 )x 40) years= 610 years.
:. Age of the teacher = (610 - 585) years=25 yANSWER B