RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: A man swims downstream 96 km and upstream 64 km taking 4 hours each time; what is the speed of the current?
A.6
B.4
C.2
D.8
Answer: B.4
Explanation: 96 --- 4 DS = 24
? ---- 1
64 ---- 4 US = 16
? ---- 1 S = ?
S = (24 - 16)/2 = 4
Answer: B
Question: Five gallons of a solution of vinegar and water with 8% vinegar is to be diluted with water to make a 4% vinegar mixture. How many gallons of water should be added?
A.10
B.5
C.4
D.2
Answer: B.5
Explanation: In these types of mixture questions, if the answers are numbers, then it's likely that you can TEST THE ANSWERS to quickly get to the solution. Here's how:
First, we need to know about the original mixture of vinegar and water. We're told that a 5 gallon mixture is 8% vinegar....
(5 gallons)(.08) = 0.4 gallons vinegar
The rest = 4.6 gallons water
We're told to ADD WATER until the mixture goes from 8% vinegar to 4% vinegar.
Since the answer choices are numbers, we know that one of them will lead us to a 4% mix when added to the current mix. Changing 8% to 4% means that we have to add a significant amount of water (relative to what we started with), so I would TEST one of the bigger numbers first.
Let's TEST B
If 5 gallons of water were added, then we'd have....
0.4 gallons vinegar
9.6 gallons of water
0.4/10 = 4% vinegar. This is EXACTLY what we're looking for, so B MUST be the answer.
Final Answer:
B
Question: A company has a job to prepare certain number of cans and there are three machines A, B and C for this job. A can complete the job in 2 days, B can complete the job in 8 days and C can complete the job in 10 days. How many days the company will it take to complete the job if all the machines are used simultaneously?
A.4/27 days
B.40/29 days
C.3/4 days
D.1/2 days
Answer: B.40/29 days
Explanation: Let the total number of cans to be prepared be 40.
The number of cans prepared by A in 1 day = 20.
The number of cans prepared by B in 1 day = 5.
The number of cans prepared by C in 1 day = 4.
Thus, the total number of cans that can be prepared by all the machines working simultaneously in a single day = 29.
Therefore, the number of days taken to complete the whole work = 40/29 days.
ANSWER:B
Question: Three hoses work to fill a tub at at different rate. Hose E and B, working together, can fill the tub in 6/5 of an hour. Hoses E and C can fill it in 3/2 an hour. Houses B and C can fill it in 2 hours. How long does it take all 3 hoses, working together, to fill the tub?
Edited for accurate solution
A.3/10
B.2/5
C.1/2
D.1
Answer: D.1
Explanation: Convert the given time to rate and you will be able to add it up.
Total Rate of E and B = Rate of E + Rate of B = 1/(6/5) = 5/6
Total Rate of E and C = Rate of E + Rate of C = 1/(3/2) = 2/3
Total Rate of B and C = Rate of B + Rate of C = 1/2
Adding all three,
2(Rate of E + Rate of B + Rate of C) = 5/6 + 2/3 + 1/2 = 2
Rate of E + Rate of B + Rate of C = 1 tub/hour
Time taken by all three together to fill up the tub is 1 hour=D
Question: A team won 50 percent of its first 60 games in a particular season, and 80 percent of its remaining games. If the team won a total of 60 percent of its games that season, what was the total number of games that the team played?
A.180
B.120
C.90
D.85
Answer: C.90
Explanation: Won 50 % of the first 60 games means it won 30 games.
Let the number of remaining games played be x. Hence the number of remaining games won is 0.8x.
So the equation for winning can be written as:
30+0.8x= 0.6(60+x)
x=30
Total games played= 60+30=90
Option C.
Question: If the price of an item is decreased by 30% and then increased by 30%, the net effect on the price of the item is
A.A decrease of 99%
B.No change
C.A decrease of 1%
D.A decrease of 9%
Answer: D.A decrease of 9%
Explanation: initially assume 100 rupees
30% discount in 100 gives price of 70 rupees
then 30% raise in 70 is only 21 rupees.
therefore total price =91 rupees.
hence 9% is the loss
ANSWER:D
Question: In how much time will a train of length 100 m, moving at 36 kmph cross an electric pole?
A.11
B.66
C.19
D.10
Answer: D.10
Explanation: Convert kmph to mps. 36 kmph = 36 * 5/18 = 10 mps.
The distance to be covered is equal to the length of the train.
Required time t = d/s = 100/10 = 10 sec.Answer: D
Question: Let Q represent a set of two distinct prime numbers. If the sum of the numbers in Q is even and x is a member of Q, then what is the least possible value that x can be?
A.1
B.5
C.3
D.2
Answer: D.2
Explanation: Q = p1+p2= even (and all primes are distinct)
if the least prime is 2 then we have sum of Q =even.
Ans. D. 2
Question: Two bus tickets from city A to B and three tickets from city A to C cost Rs. 77 but three tickets from city A to B and two tickets from city A to C cost Rs. 73. What are the fares for cities B and C from A ?
A.Rs. 13, Rs. 19
B.Rs. 13, Rs. 17
C.Rs. 13, Rs. 12
D.Rs. 13, Rs. 11
Answer: B.Rs. 13, Rs. 17
Explanation: Let Rs. x be the fare of city B from city A and Rs. y be the fare of city C from city A.
Then, 2x + 3y = 77 ...(i) and
3x + 2y = 73 ...(ii)
Multiplying (i) by 3 and (ii) by 2 and subtracting, we get: 5y = 85 or y = 17.
Answer: B
Question: A can run 128 metre in 28 seconds and B in 32 seconds. By what distance A beat B?
A.38 metre
B.28 metre
C.23 metre
D.16 metre
Answer: D.16 metre
Explanation: Clearly, A beats B by 4 seconds
Now find out how much B will run in these 4 seconds
Speed of B = Distance/Time taken by B=128/32=4 m/s
Distance covered by B in 4 seconds = Speed Ã— time =4Ã—4=16 metre
i.e., A beat B by 16 metre
Answer is D
Question: The length of a rectangle is twice its breadth if its length is decreased by 5cm and breadth is increased by 5cm, the area of the rectangle is increased by 75 sq cm. Find the length of the rectangle.
A.22
B.40
C.38
D.278
Answer: B.40
Explanation: Explanation:
let length = 2x and breadth = x then
(2x-5) (x+5) = (2x * x)+75
5x-25 = 75 => x=20
length of the rectangle = 40 cm
Answer: B) 40
Question: An investor receives a total combined return of 7% on his two different investments. On his $20,000 investment he receives a return of 6%. What is the return on his $20,000 investment?
A.7.25%
B.4.9%
C.8%
D.8.5%
Answer: C.8%
Explanation: 0.06 * 20000 + 20000x = 0.07(40000)
solving for x give x = 8%
option C
Question: In Company B, the total monthly payroll for the 20 factory workers is $36,000 and the total monthly payroll for the 50 office workers is $110,000. By how much does the average (arithmetic mean) monthly salary of an office worker exceed that of a factory worker in this company?
A.$400
B.$450
C.$500
D.$550
Answer: A.$400
Explanation: The average monthly salary of a factory worker is: $36,000 / 20 = $1800.
The average monthly salary of an office worker is: $110,000 / 50 = $2200.
The difference in average salary is: $2200 - $1800 = $400.
The answer is A.
Question: An amount of money is to be divided between P, Q and R in the ratio of 3:7:12. If the difference between the shares of P and Q is Rs.2500, what will be the difference between Q and R's share?
A.2225
B.2325
C.2425
D.2625
Answer: D.2625
Explanation: 4 --- 2100
5 --- ? => 2625
ANSWER:D
Question: Find the invalid no.from the following series 13, 18, 25, 30, 37, 40
A.13
B.18
C.40
D.37
Answer: C.40
Explanation: The differences between two successive terms from the beginning are 7, 5, 7, 5, 7, 5. So, 40 is wrong.
C
Question: A and B starts a business with Rs.8000 each, and after 4 months, B withdraws half of his capital . How should they share the profits at the end of the 17 months?
A.17:11
B.18:15
C.18:19
D.18:121
Answer: A.17:11
Explanation: A invests Rs.8000 for 17 months, but B invests Rs.8000 for the first 4 months and then withdraws Rs.4000. So, the investment of B for remaining 14 months is Rs.4000 only.
A : B
8000*17 : (8000*4) + (4000*14)
136000 : 88000
A:B = 17:11.Answer:A
Question: A boatman goes 3 km against the current of the stream in 3 hour and goes 1 km along the current in 30 minutes. How long will it take to go 3 km in stationary water?
A.5 hours
B.4 hours
C.3 hours
D.2 hours
Answer: D.2 hours
Explanation: Explanation:
Speed upstream = 3/3 = 1 km/hr
Speed downstream = 1/(30/60)= 2 km/hr
Speed in still water = 1/2(2+1)= 3/2 km/hr
Time taken to travel 3 km in still water = 3/(3/2) = 6/3 = 2 hours
Answer: Option D
Question: What is the ratio between perimeters of two squares one having 5 times the diagonal then the other?
A.3: 8
B.3: 6
C.3: 7
D.5: 1
Answer: D.5: 1
Explanation: d = 5d d = d
a√2 = 5d a√2 = d
a = 5d/√2 a = d/√2 => 5: 1
Answer:D
Question: What is the rate percent when the simple interest on Rs.600 amount to Rs.160 in 4 Years?
A.6.66%
B.7.66%
C.6.06%
D.6.16%
Answer: A.6.66%
Explanation: 160 = (600*4*R)/100
R = 6.66%
ANSWER:A
Question: A bowl contains equal numbers of red, orange, green, blue, and yellow candies. Kaz eats all of the green candies and half of the orange ones. Next, he eats half of the remaining pieces of each color. Finally, he eats red and yellow candies in equal proportions until the total number of remaining candies of all colors equals 30% of the original number. What percent of the red candies remain?
A.22.5%
B.31.5%
C.37.5%
D.42.5%
Answer: C.37.5%
Explanation: Let x be the original number of each color so there are a total of 5x candies.
Kaz eats all of the green candies and half of the orange ones.
There are 0 green candies and 0.5x orange candies remaining.
He eats half of the remaining pieces of each color.
There are 0.25x orange candies, and 0.5x each of red, yellow, and blue candies.
He eats red and yellow candies in equal proportions.
orange+blue+red+yellow = 0.75x + red + yellow = 1.5x
red + yellow = 0.75x
red = 0.375x, since red = yellow.
The answer is C.
Question: Consider two postmen A and B respectively. A is young and can deliver 20 parcels in 3 hours while B is older than A and can deliver only 15 parcels in 4 hours. If the total number of parcels to deliver is 60, how long they will take working together.
A.144/22
B.144/25
C.144/21
D.144/221
Answer: B.144/25
Explanation: Work done by 1st in 1 hour = 20/3 parcels / hour , Work done by 2nd om 1 hour = 15/4 parcels / hour
Total work done by both together per hour = 20/3 + 15/4 = 125/12 parcels/hour
Time to do 60 unit work (ie, parcels)= 60 ÷ 125/12 = 60 × 12/125 = 144/25 hours.
Answer:B
Question: Twenty five percent of Country Y's yearly exports come from fruit exports. One-fifth of all fruit exports from Country Y are orange exports. If country Y generates $10 million from its orange exports, how much money does it generate from its yearly total of exports?
A.$2125m
B.$25m
C.$200m
D.$300m
Answer: C.$200m
Explanation: 25/100*1/5*(total) = 10
1/20*(total) = 10
(total) = 10*20 = 200
Answer: C
Question: On planet korba, a solar blast has melted the ice caps on its equator. 9 years after the ice melts, tiny planetoids called echina start growing on the rocks. Echina grows in the form of circle, and the relationship between the diameter of this circle and the age of echina is given by the formula d = 4*[sqrt(t-9)] for t>9, where d represents the diameter in mm and t the number of years since the solar blast. Jagan recorded the radius of some echina at a particular spot as 7mm. How many years back did the solar blast occur?
A.17
B.21.25
C.12.25
D.14.05
Answer: B.21.25
Explanation: radius=7mm.
So dia= 14mm.
putting D=14 in equation we can easily calculate
t=21.25
ANSWER:B
Question: In a mixture 60 litres, the ratio of milk and water 2 : 1. If this ratio is to be 1 : 2, then the quanity of water to be further added is
A.50 liters
B.55 liters
C.60 liters
D.70 liters
Answer: C.60 liters
Explanation: Quantity of milk = 60 x 2 litres = 40 litres.
3
Quantity of water in it = (60- 40) litres = 20 litres.
New ratio = 1 : 2
Let quantity of water to be added further be x litres.
Then, milk : water = 40 .
20 + x
Now, 40 = 1
20 + x 2
20 + x = 80
x = 60.
Quantity of water to be added = 60 liters.
C
Question: In a school 10% of the boys are same in number as 1/4th of the girls. what is the ratio of boys to the girls in the school?
A.5:2
B.2:3
C.1:4
D.3:7
Answer: A.5:2
Explanation: 10% of B = 1/4 G
10B/100 = G/4
B = 5G/2
B/G = 5/2
B:G = 5:2
Answer is A
Question: The length of the rectangular field is double its width. Inside the field there is square shaped pond 8m long. If the area of the pond is 1/8 of the area of the field. What is the length of the field?
A.31 m
B.32 m
C.16 m
D.20 m
Answer: B.32 m
Explanation: A/8 = 8 * 8 => A = 8 * 8 * 8
x * 2x = 8 * 8 * 8
x = 16 => 2x = 32
ANSWER:B
Question: Carol and Jordan draw rectangles of equal area. If Carol's rectangle measures 5 inches by 24 inches and Jordan's rectangle is 8 inches long, how wide is Jordan's rectangle, in inches?
A.25
B.23
C.22
D.15
Answer: D.15
Explanation: Area of Carol's rectangle = 24*5 = 120
Let width of Jordan's rectangle= w
Since , the areas are equal
8w = 120
=>w = 15
Answer D
Question: At a meeting of the 3 Joint Chiefs of Staff, the Chief of Naval Operations does not want to sit next to the Chief of the National Guard Bureau. How many ways can the 3 Chiefs of Staff be seated around a circular table?
A.120
B.480
C.960
D.2520
Answer: C.960
Explanation: Bunuel, I'm also a little confused with the number of arrangements of n distinct objects in a circle. Why is it given by (n-1)!. In theveritasanswer they say:answer C (960), should be the number of ways to arrange all 7 without the seating restriction given. Is this incorrect?C
Question: If in a 20 over cricket match, there were no wide balls, no wides, no extras and no overthrows.
What is the maximum number of runs that a batsman can score in an ideal case scenario?
A.663
B.720
C.625
D.640
Answer: A.663
Explanation: Solution:
663
Explanation:
For an ideal case, the batsman will hit a six on each ball. But if he hits six on the last ball of the over, the strike will change in the next over. Thus, the best he can do in the last ball is run 3 runs so that he retains the strike even in the next over. Thus the total runs that he can score in each over:
6 * 5 + 3 = 33
But this will have to go like it only till the 19th over. In the last over, he can hit a six in the last ball as well as that will be the last ball of the match.
Thus runs for the last over will be 6 * 6 = 36.
Hence the maximum runs = 33 * 19 + 36 = 663
Answer A
Question: Two trains are running in opposite directions in the same speed. The length of each train is 120 meter. If they cross each other in 12 seconds, the speed of each train (in km/hr) is
A.42
B.36
C.28
D.20
Answer: B.36
Explanation: Explanation:
Distance covered = 120+120 = 240 m
Time = 12 s
Let the speed of each train = v. Then relative speed = v + v = 2v
2v = distance/time = 240/12 = 20 m/s
Speed of each train = v = 20/2 = 10 m/s
= 10 × 36/10 km/hr = 36 km/hr.
Answer: B
Question: In a hostel of 12 boys and some girls, an average consumption of rice per month is 12 kg, while the Average consumption for boys is 16 kg per head and for girls 8 kg per head. The number of girls in The hostel?
A.12
B.13
C.14
D.15
Answer: A.12
Explanation: Explanation:
Number of girls — G
(12+G) × 12 = (12 × 16)+(8 × G)
144 + 12G = 192 + 8G
12G − 8G = 192 − 144
4G = 48
G = 12.
Answer A
Question: The speed of a boat in still water is 12 km/hr and the rate of current is 4 km/hr. The distance travelled downstream in 18 minutes is
A.1.6 km
B.2 km
C.3.6 km
D.4.8 km
Answer: D.4.8 km
Explanation: Explanation:
Speed downstreams	=(12 + 4)kmph
= 16 kmph.
Distance travelled	= (16 x 18/60)km
= 4.8km
Option D
Question: If dy > 0 and yz < 0, which of the following must be negative:
A.dyz
B.dy(z^2)
C.d(y^2)z
D.x(y^2)(z^2)
Answer: C.d(y^2)z
Explanation: dy > 0 means that dy is positive.
yz < 0 means that yz is negative.
d(y^2)z = (dy)(yz) = positive*negative = negative. Thus option C is always negative.
Question: If the cost price of 11 pens is equal to the selling price of 10 pens, the gain percent is:
A.10%
B.26%
C.50%
D.80%
Answer: A.10%
Explanation: Solution :
Let cost price of the price be Rs.1
10 pens C.P. = 10
11 pens S.P. = 11
Gain = 1/10*100 = 10 %
Answer : A
Question: By walking at 3/4th of his usual speed, a man reaches office 20 minutes later than usual. What is his usual time?
A.40min
B.50min
C.65min
D.60min
Answer: D.60min
Explanation: let T be the usual time.
time spent=4T/3
therefore, 4T/3=T+20
4T=3T+60...therefor T=60min
ANSWER:D
Question: Mr. Thomas invested an amount of Rs. 13,900 divided in two different schemes A and B at the simple interest rate of 14% p.a. and 11% p.a. respectively. If the total amount of simple interest earned in 2 years be Rs. 3508, what was the amount invested in Scheme B?
A.6400
B.7300
C.6438
D.6439
Answer: A.6400
Explanation: Let the sum invested in Scheme A be Rs. x and that in Scheme B be Rs. (13900 - x).
Then, x x 14 x 2	/100	+ (13900 - x) x 11 x 2	/100	= 3508
28x - 22x = 350800 - (13900 x 22)
6x = 45000
x = 7500.
So, sum invested in Scheme B = Rs. (13900 - 7500) = Rs. 6400.
Answer:A
Question: The mean daily profit made by a shopkeeper in a month of 30 days was Rs. 350. If the mean profit for the first fifteen days was Rs. 285, then the mean profit for the last 15 days would be
A.Rs. 200
B.Rs. 350
C.Rs. 275
D.Rs. 415
Answer: D.Rs. 415
Explanation: Average would be : 350 = (285 + x)/2
On solving, x = 415.
Answer: D
Question: Rajeev,Lakshmi and Muthu enter into partnership. Rajeev invests some money at the beginning, Lakshmi invests double the amount after 6 months, and Muthu invests thrice the amount after 8 months. If the annual gain be Rs.4500. Lakshmi's share is?
A.1000
B.1500
C.500
D.750
Answer: B.1500
Explanation: x* 12 : 2x* 6: 3x* 4
1:1:1
1/3 * 4500 = 1500
Answer: B
Question: A flagstaff 17.5 m high casts a shadow of length 40.25 m.The height of the building,which casts a shadow of length 28.75 m under similar conditions will be :
A.10 m
B.12.5 m
C.17.5 m
D.21.25 m
Answer: B.12.5 m
Explanation: Solution
14.8
Let the height of the building be x meters.
Less lengthy shadow,Less is the height(Direct Proportion)
∴ 40.25 : 28.75 : : 17.5 : x ⇔ 40.25 × x = 28.75 × 17.5
⇔ x =(28.75x17.50)/ 40.25 ⇔ x = 12.5, Answer B
Question: The contents of a bag of candy consist of 11 green pieces of candy and 20 blue pieces of candy. How many blue pieces of candy must be eaten so that 55% of the candies in the bag will be green?
A.8
B.10
C.11
D.13
Answer: C.11
Explanation: This question is rooted in basic arithmetic. Since the question asks how many marbles need to be removed and the answers ARE numbers, we can TEST THE ANSWERS until we find the one thatfits.
To start, we have a bag of candy....
11 green
20 blue
31 total
We're asked to eat enough blue candies until the green candies make up 55% of the bag....
Right now, green marbles make up 11/31 which equals about 35% of the bag, we need to eat blue candy to achieve green candies making up for 55% of the bag. We can test our answers
Let's TEST B....
IF 10 blue candies were eaten, then we'd have...
11 green candies
10 blue candies
21 total
11/21 is about 52%.
Let's TEST E...
IF 11 blue candies were eaten, then we'd have...
11 green candies
9 blue candies
20 total
11/20 IS 55%, so this MUST be the answer!
Final Answer:
C
Question: If a card is drawn from a well shuffled pack of cards, the probability of drawing a spade or a king is?
A.4/16
B.4/19
C.4/12
D.4/13
Answer: D.4/13
Explanation: P(SᴜK) = P(S) + P(K) - P(S∩K), where S denotes spade and K denotes king.
P(SᴜK) = 13/52 + 4/52 - 1/52 = 4/13
Answer:D
Question: A rope of which a calf is tied is increased from 12 m to 23 m, how much additional grassy ground shall it graze?
A.1298
B.1228
C.1210
D.1782
Answer: C.1210
Explanation: π (232 – 122)
= 1210
Answer:C
Question: A cistern is filled by a tap in 3 1/2 hours. Due to leak in the bottom of the cistern, it takes half an hour longer to fill the cistern. If the cistern is full how long will it take the leak to empty it?
A.7 hours
B.8 hours
C.14 hours
D.28 hours
Answer: D.28 hours
Explanation: 2/7 - 1/x = 1/4
x = 28
ANSWER:D
Question: Eighteen years ago, a father was three times as old as his son. Now the father is only twice as old his son. Then the sum of the present ages of the son and the father is:
A.54
B.72
C.105
D.108
Answer: D.108
Explanation: Answer: Option D
Let the present ages of the father and son be 2x and x years respectively.
Then, (2x - 18) = 3(x - 18) => x = 36
Required sum = (2x + x) = 108 years.
Question: The speed of a boat in still water in 42 km/hr and the rate of current is 4 km/hr. The distance travelled downstream in 44 minutes is:
A.86.6 km
B.46.6 km
C.33.7 km
D.35.6 km
Answer: C.33.7 km
Explanation: Speed downstream = (42 + 4) = 46 kmph
Time = 44 minutes =44/60 hour = 11/15 hour
Distance travelled = Time × speed =11/15×46 = 33.7 km
ANSWER:C
Question: If the compound interest (compounded Yearly) on a certain sum for 2 years at 3% is Rs.101.50 then what will be the corresponding simple interest?
A.Rs.98.25
B.Rs.101.00
C.Rs.90.00
D.Rs.95.50
Answer: B.Rs.101.00
Explanation: simple interest=50+50
compound interest=50+(50+50*0.3)=101.50
ANSWER:B
Question: A train running at the speed of 70 km/hr crosses a pole in 9 sec. What is the length of the train?
A.298 m
B.175 m
C.208 m
D.988 m
Answer: B.175 m
Explanation: Speed = 70 * 5/18 = 175/9 m/sec
Length of the train = speed * time = 175/9 * 9
= 175 m
Answer:B
Question: Two trains of equal lengths take 10 sec and 8 sec respectively to cross a telegraph post. If the length of each train be 120 m, in what time will they cross other travelling in opposite direction?
A.22
B.12
C.9
D.99
Answer: C.9
Explanation: Speed of the first train = 120/10 = 12 m/sec.
Speed of the second train = 120/8 = 15 m/sec.
Relative speed = 12 + 15 = 27 m/sec.
Required time = (120 + 120)/27 = 9 sec.
Answer: C
Question: The average weight of 7 person's increases by 6.2 kg when a new person comes in place of one of them weighing 76 kg. What might be the weight of the new person?
A.160 kg
B.175 kg
C.180.7 kg
D.119.4 kg
Answer: D.119.4 kg
Explanation: Total weight increased = (7 x 6.2) kg = 43.4 kg.
Weight of new person = (76 + 43.4) kg = 119.4 kg
Option D
Question: Sides of a rectangular park are in the ratio 3: 2 and its area is 3750 sq m, the cost of fencing it at 50 ps per meter is?
A.288
B.277
C.298
D.125
Answer: C.298
Explanation: 3x * 2x = 3750 => x = 25
2(75 + 50) = 250 m
250 * 1/2 = Rs.125.Answer:C
Question: A boatman can row 96 km downstream in 8 hr. If the speed of the current is 4 km/hr, then find in what time he will be able to cover 8 km upstream ?
A.1.5 hrs
B.1 hrs
C.2.5 hrs
D.2 hrs
Answer: D.2 hrs
Explanation: Explanation:
Speed in downstream = 96/8 = 12 kmph
Speed of current = 4 km/hr
Speed of the boatman in still water = 12 â€“ 4 = 8 kmph
Speed in upstream = 8 â€“ 4 = 4 kmph
Time taken to cover 8 km upstream = 8/4 = 2 hours.
ANSWER IS D
Question: How many integer values T are there for x such that 1 < 3x + 5 < 17?
A.Two
B.Three
C.Four
D.Five
Answer: D.Five
Explanation: 1 < 3x + 5 < 17
=> -4 < 3x < 12
=> -4/3 < x < 4
x can take integer values T -1,0 , 1 , 2 , 3
Answer D
Question: The average of marks obtained by 120 boys was 36. If the average of marks of passed boys was 39 and that of failed boys was 15, the number of boys who passed the examination is?
A.105
B.110
C.120
D.130
Answer: A.105
Explanation: Let the number of boys who passed = X.
Then, 39 x X + 15 x (120 - X) = 120 x 36
24X = 4320 - 1800
=> X = 2520/24
X = 105.
Hence, the number of boys passed = 105.
ANSWER:A
Question: The distance light travels in one year is approximately 5,860,000,000,000 miles. The distance light travels in 100 years is
A.A) 587 × 108 miles
B.B) 587 × 1010 miles
C.C) 587 × 10-10 miles
D.D) 586 × 1012 miles
Answer: D.D) 586 × 1012 miles
Explanation: The distance of the light travels in 100 years is:
5,860,000,000,000 × 100 miles.
= 586,000,000,000,000 miles.
= 586 × 1012 miles.
The answer is (D)
Question: The difference between the simple interest received from two different sources on Rs.1900 for 3 years is Rs.13.50. The difference between their rates of interest is
A.0.13%
B.0.23%
C.0.33%
D.0.43%
Answer: B.0.23%
Explanation: (1900xR1x3)/100-(100xR2x3)/100 =13.50
5700(R1-R2)=1350
R1-R2 = 1350/5700=0.23%
answer : B