RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: If 12!/3^x is an integer, what is the greatest possible value of x?
A.3
B.4
C.5
D.6
Answer: C.5
Explanation: This question is asking how many power of 3 exists in 12!
easiest way is to identify factor of three
12 -> 4*3 => 1 power of 3
9 -> 3*3=> 2 power of 3
6 -> 2*3=> 1 power of 3
3 -> 1*3=> 1 power of 3
Total equal 5
ANSWER:C
Question: Number of prime numbers between 70 and 100 is
A.4
B.5
C.6
D.7
Answer: C.6
Explanation: total 6=71, 73, 79, 83, 89, 97
ANSWER:C
Question: Carl is facing very difficult financial times and can only pay the interest on a $10,000 loan he has taken. The bank charges him a quarterly compound rate of 4%. What is the approximate interest he pays annually?
A.$1750
B.$2000
C.$2150
D.$2500
Answer: A.$1750
Explanation: An easy way too attempt this is by approximation:
For the first quarter, he pays 4% of 10,000 which is $400.
So for the four quarters in the year, he will approximately play 400*4=1600 over the entire year.
Because of compound interest it will be more than 1600. Approx. option A is correct.
Answer : A
Question: If x ≠ 0 and y/x=y+x, which of the following expressions is equal to its opposite?
A.x^2
B.x^2 – y^2
C.y^2
D.x^2 + xy - y^2
Answer: D.x^2 + xy - y^2
Explanation: y/x=(y+x)/y
=> y^2 = xy +x^2
=> x^2 + xy - y^2= 0
Answer D
Question: In a renowned city, the average birth rate is 5 people every two seconds and the death rate is 3 people every two seconds. Estimate the size of the population net increase that occurs in one day.
A. 85,400
B. 86,400
C. 87,400
D. 88,400
Answer: B. 86,400
Explanation: This question can be modified so that the birth rate is given every m seconds and the death rate is given every n seconds.
For this particular question : Increase in the population every 2 seconds = 5-3 = 2 people.
Total 2 second interval in a day = 24*60*60/2 = 43,200
Population increase = 43,200 * 2 = 86,400. Hence B.
Question: A bag contains a certain number of 50 paise coins, 20 paise coins and 10 paise coins inthe ratio 3:4:5. If the total value of all the coins in the bag is Rs.350, find the number of 50 paise coins ?
A.498
B.488
C.375
D.528
Answer: C.375
Explanation: 50*3k + 20*4k + 10*5k = 35000
280k = 35000 => k = 125
50p coins = 3k = 3*125 = 375
ANSWER:C
Question: The cost price of three varieties of oranges namely A, B and C is Rs 20/kg, Rs 40/kg and Rs 50/kg. Find the selling price of one kg of orange in which these three varieties of oranges are mixed in the ratio of 2 : 3 : 5 such that there is a net profit of 20%?
A.Rs 48
B.Rs 48.6
C.Rs 49.2
D.Rs 49.8
Answer: C.Rs 49.2
Explanation: Cost price of one kg of orange in which the three varieties of oranges are mixed in the ratio 2 : 3 : 5 is equal to S where
S = 0.2 x 20 + 0.3 x 40 + 0.5 × 50
= 4 + 12 + 25
= Rs 41
Selling price per kg of oranges to ensure there is a net profit of 20%
= 1.2 x 41
= Rs 49.2
ANSWER:C
Question: A certain class of students is being divided into teams. The class can either be divided into 8 teams with an equal number of players on each team or 24 teams with an equal number of players on each team. What is the lowest possible number of students in the class?
A.6
B.36
C.48
D.24
Answer: D.24
Explanation: Let total no of students in the class be N
So, we are told that N is divisible by both 8 24
So, Lets find the least common multiple of 8 24 , ie 24
So our answer is (D) 24
Question: If x = -3/7 and y = -2/3, what is the value of the expression -2x – y^2?
A.-33/22
B.23/85
C.26/63
D.58/41
Answer: C.26/63
Explanation: x = -3/7 and y = -2/3
==> -2(-3/7) - (2/3)^2 = 6/7 - 4/9 = 26/63
Ans: C
Question: Find the simple interest on $2500 for 3 years at 10% per annum?
A.$250
B.$300
C.$750
D.$600
Answer: C.$750
Explanation: SI = PTR/100
= 2500*3*10/100 = $750
Answer is C
Question: A boat takes 90 minutes less to travel 36 miles downstream than to travel the same distance upstream. If the speed of the boat in still water is 10 mph, the speed of the stream is
A.2 mph
B.2.5 mph
C.3 mph
D.4 mph
Answer: A.2 mph
Explanation: Let the speed of the stream x mph.
Speed downstream = (10 + x) mph.
Speed upstream = (10 - x) mph.
36/(10-x)-36/(10+x)=90/60
72x x 60 = 90(100-x2)
x2+48x-100 = 0
(x+ 50)(x - 2) = 0
x = 2 mph.
ANSWER:A
Question: What is the remainder when 6990990900032 is divided by 32 ?
A.5
B.0
C.4
D.2
Answer: B.0
Explanation: Though i was unaware of the divisibility test for 32 but i guessed the pattern!!
divisibility rule for 4- last two digits must be divisible by 4
divisibility rule for 8- last three digits must be divisible by 8
similarly, divisibility rule for 32 - last five digits must be divisible by 32
Hence, Ans B
Question: Which of the following points is closest to line y=x
A.(2, -1)
B.(2, 4)
C.(-1, 1)
D.(1, 2)
Answer: D.(1, 2)
Explanation: Attachment:
m12-20.pngAs you can see point (1, 2) is the closest to line y=x.
Answer: D.
Question: What is the average (arithmetic mean) of the numbers 2, 4, 6, 8, 10, 12, 14 and 16?
A.9
B.10
C.15
D.12
Answer: A.9
Explanation: avg = sum of observations/number of observations
avg =(2+4+6+8+10+12+14+16)/8 = 9
Answer is A
Question: What is the greatest integer that will always evenly divide the sum of three consecutive integers?
A.2
B.3
C.4
D.6
Answer: B.3
Explanation: Let the three consecutive integers be x , x + 1 , x + 2
Sum = x + x + 1 + x + 2
= 3x+3 = 3(x+1)
Therefore , 3 will always be a factor .
Answer B
Question: A delegation of 5 members has to be formed from 3 ladies and 5 gentlemen. In how many ways the delegation can be formed, if 2 particular ladies are always included in the delegation?
A.20
B.82
C.82
D.25
Answer: A.20
Explanation: Explanation:
There are three ladies and five gentlemen and a committee of 5 members to be formed.
Number of ways such that two ladies are always included in the committee = ⁶C₃ = (6 * 5 * 4)/6 = 20.
Answer:A
Question: A ship sails out to a mark at the rate of 15 kmph. and sails back at the rate of 10 kmph. The average rate of sailing is ?
A.5 km/hr
B.12 km/hr
C.12.5 km/hr
D.25 km/hr
Answer: B.12 km/hr
Explanation: Answer
Average = ( 2uv / u +v ) km/hr
= ( 2 x 15 x 10 ) / (15 +10 ) km/hr.
= 12 km/hr.
Correct Option: B
Question: The unit digit in the product (594 * 897* 929 * 462) is:
A.2
B.5
C.6
D.4
Answer: D.4
Explanation: Explanation:
Unit digit in the given product = Unit Digit in (4*7*9*2) = 4
ANSWER: D
Question: A shipment of 1500 heads of cabbage, each of which was approximately the same size was purchased for $600.The day the shipment arrived 2/3 of the heads were sold, each at 25% above the cost per head.The following day the rest were sold at a price per head equal to 18% less than the price each head sold for the day before.what was the gross profit on this shipment?
A.$105
B.$115
C.$125
D.$130
Answer: A.$105
Explanation: Sol:
1500 heads -> $600
1 head -> $600/1500
1 head -> $(2/5)
25% more of (2/5) -> 125/100 * 2/5 = $(1/2)
He sold 2/3*1500 = 1000 heads for $(1/2) per head
Total revenue by selling 1000 heads = 1000 * 1/2 = $500
Heads left: 500
Cost per head: 82% of the previous price: 82/100 * 1/2 = $(16/39)
Total revenue by selling 500 heads = 16/39 * 500 = 205
Total revenue after selling 1500 cabbage heads - 205+500 = $705
Money spent on the purchase: $600
Profit = 705-600 = $105
Ans: A
Question: How much time will it take for an amount of 450 to yield 81 as interest at 4.5% per annum of simple interest?
A.3 years
B.4 years
C.6 years
D.5 years
Answer: B.4 years
Explanation: Time = (100 x 81)/(450 x 4.5) years = 4 years.
answer B
Question: Ramu bought an old car for Rs. 40000. He spent Rs. 13000 on repairs and sold it for Rs. 64900. What is his profit percent?
A.A)14%
B.B)16%
C.C)18%
D.D)21.6%
Answer: D.D)21.6%
Explanation: Total CP = Rs. 40000 + Rs. 13000 = Rs. 53000 and SP = Rs. 64900
Profit(%) = (64900 - 53000)/55000 * 100 = 21.6%
ANSWER:D
Question: If the sum of a set of 5 different positive prime numbers is 94, what is the difference between largest and smallest prime numbers between them?
A.53
B.51
C.47
D.41
Answer: D.41
Explanation: All prime numbers apart from 2 are odd.
Even + Even = Even
Odd + Even = Odd
Odd + Odd = Even
We are given 5 different prime numbers, whose sum is 94 i.e even
If we include 2, we will have 4 odd prime numbers and one even.
This sum would be odd
If we exclude 2, we will have 5 odd numbers.
This sum would be even
Hence 2 is included.
The possible 5 no. are = 11+7+2+43+31 = 94
the difference between largest and smallest prime numbers between them = 43 - 2 = 41
Ans - D
Question: The ratio of investments of two partners P and Q is 7:5 and the ratio of their profits is 7:10. If P invested the money for 5 months, find for how much time did Q invest the money?
A.28
B.10
C.288
D.277
Answer: B.10
Explanation: 7*5: 5*x = 7:10
x = 10
Answer: B
Question: Ms. Mary sold two properties, X and Y, for $40,000 each. She sold property X for 20 % more than she paid for it and sold property Y for 20% less than she paid for it. If expenses are disregarded , what was her total net gain or loss, if any, on the two properties ?
A.$3233.33
B.$3433.33
C.$3333.33
D.$3533.33
Answer: C.$3333.33
Explanation: There is a property to solve such questions withCommon Selling PriceandCommon %gain and loss. such cases always result in a loss and...
Total %Loss = (Common Gain% or Loss%/10)^2
Hence Here Loss% = (20/10)^2 = 4%
which means he recovered only 96% of his investment which amount to a total revenue = 40000 + 40000 = 80000
i.e. 96% of cost = 80000
therefore, 4% of cost (Loss) = $3333.33
Answer: C
Question: The jogging track in a sports complex is 850 m in circumference. Rakesh and his wife start from the same point and walk in opposite directions at 4.2 km/hr and 3.3 km/hr respectively. They will meet for the first time in?
A.5.9 min
B.6.8 min
C.7.2 min
D.8.5 min
Answer: B.6.8 min
Explanation: Clearly, the two will meet when they are 850m apart.
To be (4.2 + 3.3) =7.5 km apart, they take 1 hour.
To be 850 m apart, they take
= (850/7500 * 60) min
= 6.8 min.
Answer: B
Question: Three partners shared the profit in a business in the ratio 5 : 7 : 8. They had partnered for 14 months, 8 months and 7 months respectively. What was the ratio of their investments?
A.5 : 7 : 8
B.20 : 49 : 64
C.38 : 28 : 21
D.3:7:9
Answer: B.20 : 49 : 64
Explanation: Let their investments be Rs. x for 14 months, Rs. y for 8 months and Rs. z for 7 months respectively.
Then, 14x : 8y : 7z = 5 : 7 : 8.
Now,	14x/8y=5/7
then 98x = 40y
then y =	49/20x
And,	14x/7z=5/8
then112x= 35z
and z =(112/35 )x =(16/5 )x.
x : y : z = x :	(49/20)x	:(16/20)x	= 20 : 49 : 64
ANSWER:B
Question: A person purchases 90 clocks and sells 40 clocks at a gain of 10% and 50 clocks at a gain of 20%. If he sold all of them at a uniform profit of 15%, then he would have got Rs. 40 less. The cost price of each clock is?
A.26
B.28
C.80
D.26
Answer: C.80
Explanation: Let C.P. of clock be Rs. x.
Then, C.P. of 90 clocks = Rs. 90x.
[(110% of 40x) + (120% of 50x)] - (115% of 90x) = 40
44x + 60x - 103.5x = 40
0.5x = 40 => x = 80
Answer: C
Question: A and B together can complete work in 6 days. A alone starts working and leaves it after working for 3 days completing only half of the work. In how many days it can be completed if the remaining job is undertaken by B?
A.3
B.8
C.5
D.6
Answer: A.3
Explanation: Explanation:
(A+B) one day work =1/6
now A does half of the work in 3 days so A can complete the whole work in 6 days
A’s one day work =1/6
B’s one day work=1/6 - 1/6= 1/6
B alone can complete the work in 6 days so half of the work in 3 days
Answer: Option A
Question: If TEAR is coded as 4657 and BOX is coded as 125. How is BETA coded?
A.1465
B.1645
C.1654
D.1456
Answer: B.1645
Explanation: e=6 t-4 a-5 from the code TEAR, b-1 from the code BOX, ANSWER:B
Question: If 20 typists can type 44 letters in 20 minutes, then how many letters will 30 typists working at the same rate complete in 1 hour?
A.63
B.72
C.198
D.216
Answer: C.198
Explanation: 20 typists can type 44 letters, so 30 typists can type = 44*30/20
44*30/20 letters can be typed in 20 mins. In 60 mins typist can type= 44*30*60/20*20= 198
C is the answer
Question: What is the 29th digit to the right of the decimal point in the decimal form of 4/11?
A.1
B.2
C.3
D.4
Answer: C.3
Explanation: 4/11 = 0.363636...
The odd numbered positions in the decimal expansion are all 3.
The answer is C.
Question: 20 buckets of water fill a tank when the capacity of each bucket is 13.5 litres. How many buckets will be required to fill the same tank if the capacity of each bucket is 9 litres?
A.30
B.32
C.60
D.Data inadequate
Answer: A.30
Explanation: Capacity of the tank = 20 × 13.5= 270 litres
When the capacity of each bucket = 9 litres, then the required no. of buckets
= 270⁄9 = 30
Answer A
Question: Mane and Thomas are among the 8 people from which a committee of 4 people is to be selected. How many different possible committees of 4 people can be selected from these 8 people if at least one of either Mane or Thomas is to be selected?
A.28
B.46
C.55
D.63
Answer: C.55
Explanation: Ans:C
Solution:
M+T+6 = total 8 ,
we need to select at least one of the M and T or both= total 4 out of 8 - 4 out of 6
8C4 - 6C4
=55
Question: There are a lot of houses such that the numbers of their doorplates are odd numbers and the first number of the doorplates is 545, the last number of the doorplates is 855. How many houses are there?
A.155
B.161
C.154
D.156
Answer: D.156
Explanation: So it starts from 545 and goes like 547, 549,...... 855. and both first and last number are inclusive. Since every other number is odd, it's just 1/2 of the numbers and since it starts with an odd and ends with an odd inclusive add one to the result.
i.e., ([855-545][/2]+1 = 156
Ans D
Question: Robert is travelling on his cycle andhas calculated to reach point A at 2 PM. if he travels at 10 kmph, he will reach there at 12Pm if he travels at 15 kmph. At what speed musthe travel to reach A at 1 PM?
A.8 kmph
B.10 kmph
C.12 kmph
D.14 kmph
Answer: C.12 kmph
Explanation: Let the distance travelled by x km.
Then, x - x = 2
10 15
3x - 2x = 60
x = 60 km.
Time taken to travel 60 km at 10 km/hr = 60 hrs = 6 hrs.
10
So, Robert started 6 hours before 2 P.M. i.e., at 8 A.M.
Required speed = 60 kmph. = 12 kmph.
5
C
Question: If the average (arithmetic mean) of x and y is 60, and z – x = 80, what is the average of y and z?
A.100
B.120
C.125
D.115
Answer: A.100
Explanation: x+y/2 = 60
=> x+y = 120
x = z - 80...sub this value
z-80+y = 120
=>z+y = 200
=>z+y/2 = 100
Answer : A
Question: At what time, in minutes, between 3 o'clock and 4 o'clock, both the needles will coincide each other?
A.16 4/17
B.16 4/16
C.16 4/12
D.16 4/11
Answer: D.16 4/11
Explanation: At 3 o'clock, the minute hand is 15 min. spaces apart from the hour hand.
To be coincident, it must gain 15 min. spaces.55 min. are gained in 60 min.
15 min. are gained in
= (60/55 x 15)min
=16+4/11
The hands are coincident at 16 + 4/11 min past 3
Answer: D
Question: In a shower, 9 cm of rain falls. The volume of water that falls on 1.5 hectares of ground is:
A.75 cu. m
B.1350 cu. m
C.7500 cu. m
D.75000 cu. m
Answer: B.1350 cu. m
Explanation: 1 hectare = 10000 sq mtr
The volume of water that falls on 1.5 hectares of ground = 0.09*1.5*10000 =1350 cub mtr .
ANSWER:B
Question: Find the odd man out. 3576, 1784, 888, 440, 216, 105, 48
A.105
B.216
C.888
D.1784
Answer: A.105
Explanation: Explanation :
3576
(3576-8)/2 = 1784
(1784-8)/2 = 888
(888-8)/2 = 440
(440-8)/2 = 216
(216-8)/2 = 104
(104-8)/2 = 48
Hence, 105 is wrong. 104 should have come in place of 105
Answer : Option A
Question: A and B invest in a business in the ratio 3: 2. Assume that 5% of the total profit goes to charity. If A's share is Rs. 855, what is the total profit?
A.1500
B.2000
C.3000
D.3500
Answer: A.1500
Explanation: Profit as x
since 5% and 95% of x will be divided b/w A and B ration 3:2
=>profit 95x/100 * 3/5
given that A's share is Rs 855 =>
95x/100 * 3/5 = 855
hence x = 1500
ANSWER A
Question: x, y and z are consecutive positive integers such that x < y < z; which of the following must be true?
1. xyz is divisible by 6
2. (z-x)(y-x+2) = 4
3. xy is odd
A.I only
B.II only
C.III only
D.I only
Answer: D.I only
Explanation: Since x, y and z are consecutive integers such that x < y < z, we can say x = y-1 and Z = y+1
Statement 1 would be true as at least one of the three numbers is divisible by 2 and one by 3 so xyz would be divisible by 6.
Statement 2 can be simplified if we write everything in terms of y as ((y+1)-(y-1))*(y-(y-1)+2) = 2*3 = 6 So, not true
Statement 3 talks about xy Since x and y are consecutive integers one of them is odd and other is even so product would always be even and hence not true.
So, I is always true and hence answer is
D.
Question: Concentrated pineapple juice comes inside a cylinder tube with a radius of 2.5 inches and a height of 15 inches. The tubes are packed into wooden boxes, each with dimensions of 11 inches by 10 inches by 31 inches. How many tubes of concentrated pineapple juice, at the most, can fit into 3 wooden boxes?
A.24.
B.28.
C.36.
D.42.
Answer: A.24.
Explanation: concentrated pineapple juice since height of a tube is 15 inches , the tubes can fit only in one way .
now, diameter of each tube = 5 inches
therefore, 4*2 can be put in each wooden box
in 3 boxes 3*4*2 can be accommodated
= 24=A
Question: If x, y, and z are positive integers such that x is a factor of y and y is a factor of z, which of the following is NOT necessarily an integer?
A.(x + y)/z
B.(y + z)/x
C.yz/x
D.(2y + 3z)/x
Answer: A.(x + y)/z
Explanation: As per the question, let x = 2, y = 6, and z = 12. Plugging these into the answer choices, only A does not yield an integer.
Question: A sum was put at simple interest at a certain rate for 10 years . Had it been put at 5% higher rate , it would have fetched Rs.300 more. What was the Sum?
A.s.1200
B.s.1300
C.s.600
D.s.800
Answer: C.s.600
Explanation: At 5% more rate, the increase in S.I for 10 years = Rs.300 (given)
So, at 5% more rate, the increase in SI for 1 year = 300/10 = Rs.30/-
i.e. Rs.30 is 5% of the invested sum
So, 1% of the invested sum = 30/5
Therefore, the invested sum = 30 × 100/5 = Rs.600 Answer: C
Question: If y is a given positive integer,.What is the remainder if y is divided by 25, since when y divided by 7 and 12 the remainders are 4 and 3 respectively.
A.12
B.Between 1 and5, inclusive
C.Between 10 and 15, inclusive
D.Between 6 and 9, inclusive
Answer: C.Between 10 and 15, inclusive
Explanation: Given the integer y
7y+4= 12y+3
Start 7y+4 -->11, 18, 25,32,39,...
Of these only 39 fit the description 12y+3. The remainder when divided by 25 is 14. So answer is C).
Answer = C)
Question: Two teams participating in a competition had to take a test in a given time. Team
B chose the easier test with 300 questions, and team A the difficult test with 10%less questions. Team A completed the test 3 hours before schedule while team B completed it 6 hours before schedule. If team B answered 7 questions more than
team A per hour, how many questions did team B answer per hour?
A.21
B.22
C.23
D.25
Answer: D.25
Explanation: If t hrs is normal time,
then
270/(t-3) + 7 = 300/(t-6)
so t = 18
so Qns done by team A per hour = 270/15 = 18 qns.
Qns done by team B per hour = 300/12 = 25 qns.
ANSWER:D
Question: A does half as much work as Band C does half as much work as A and B together. If C alone can finish the work in 44 days, then together ,all will finish the work in :
A.13 3/3 days
B.12 1/3 days
C.15 days
D.20 days
Answer: A.13 3/3 days
Explanation: C alone can finish the work in 44 days.
(A + B)can do it in 20 days
(A + B)s 1 days wok = 1/20.
As 1 days work : Bs 1 days Work = 1/2 : 1 = 1:2.
Aâ€™s 1 dayâ€™s work = (1/20) * (1/3) = (1/60). [Divide 1/20 in the raio 1:2] Bs 1 days work = (1/20) * (2/3) = 1/30
(A+B+c)S 1 dayâ€™s work = (1/60) + (1/30) + (1/44) = 1/(13 3/4)
All the three together will finish it in = 13 and 3/4 days.
ANSWER:A
Question: A person spends 1/5th of his income on the education of his children, and 20% of the remaining on food. If he is left with Rs.576 find his income?
A.900
B.197
C.176
D.107
Answer: A.900
Explanation: X * 4/5 * 80/100 = 576
X = 14400/16
X = 900
Answer: A
Question: Evaluate combination
99C97=99!/(97)!(2)!
A.6170
B.4851
C.4171
D.3170
Answer: B.4851
Explanation: Explanation:
nCr=n!/(r)!(n−r)!
99C97=99!/(97)!(2)!
=99∗98∗97!/(97)!(2)!
=99∗98/2∗1
=4851 Option B
Question: A certain factory produces buttons and buckles at a uniform weight. If the total weight of 2 buttons and 2 buckles is one third of 11 buckles and 3 buttons, then the weight of 3 buttons and 2 buckles is how many times that of 5 buckles and 6 buttons?
A.7/15
B.4/9.
C.6/11
D.5/9
Answer: A.7/15
Explanation: 2 buttons + 2 buckles = 1/3(11 buckles + 3buttons)
6 buttons + 6 buckles = 11 buckles + 3buttons
3buttons = buckles
Weight of 3buttons and buckles = 5buckles + 2buckles = 7buckles
Weight of 6buttons and 5buckles = 10buckles + 5buckles = 15buckles
(3buttons and 2buckles) = x * (6buttons and 5buckles)
7 = x*15
x = 7/15
Answer: A
Question: How many of the following numbers are divisible by 132?
264, 396, 462, 792, 968, 2178, 5184, 6336, 528
A.4
B.5
C.6
D.7
Answer: B.5
Explanation: Explanation:
A number is divisible by 132, if it is divisible by each one of 11, 3 and 4.
Clearly, 968 is not divisible by 3. None of 462 and 2178 is divisible by 4.
Also, 5184 is not divisible by 11.
Each one of remaining 5 is divisible by each one of 11, 3 and 4 and therefore, by 132.
Answer: B
Question: Ram was asked to multiply a number by 441 and he came with an answer 70229. His
Teacher told him that all the digits except the 2’s in his answer are correct. Which of the following could be the correct answer?
A.70119
B.70110
C.70117
D.70112
Answer: A.70119
Explanation: 441*158 = 69678
441*159 = 70119
441*160 = 70560
441*161 = 71001
since all the digits except 2 are correct , second number will be 159 and answer = 70119
ANSWER:A
Question: A man sitting in a train which is travelling at 20 kmph observes that a goods train, travelling in opposite direction, takes 9 seconds to pass him. If the goods train is 280 m long, find its speed?
A.52 kmph.
B.62 kmph.
C.72 kmph.
D.92 kmph.
Answer: D.92 kmph.
Explanation: Solution
Relative Speed	= (280 / 9)m/sec
= (280/9 x 18/5)
= 112 kmph.
Speed of the train	= (112 - 20)kmph
= 92 kmph.
Answer D
Question: If the two-digit integers L and N are positive and have the same digits, but in reverse order, which of the following CANNOT be the sum of L and N?
A.181
B.165
C.121
D.99
Answer: A.181
Explanation: Since the question asks for the answer that CANNOT be the sum of L and N, and the answers are numbers, we can use a combination of TESTing VALUES and TESTing THE ANSWERS to eliminate the possible values and find the answer to the question.
We're told that L and N are two-digit positive integers and have the SAME DIGITS but in REVERSE ORDER. We're asked which of the 5 answers CANNOT be the SUM of L and N.
Let's start with the 'easiest' answer first:
44. Can we get to 44 in the manner described?
Yes, if the numbers are 13 and 31.....13+31 = 44. Eliminate Answer E
Now let's work through the rest of the list....
Can we get to 99 in the manner described?
Yes, there are several ways to do it. For example, if the numbers are 18 and 81.....18+81 = 99. Eliminate Answer D
Can we get to 121 in the manner described?
Yes, there are several ways to do it. For example, if the numbers are 38 and 83.....38+83 = 121. Eliminate Answer C
Can we get to 165 in the manner described?
Yes, there are a couple of ways to do it. For example, if the numbers are 78 and 87.....78+87 = 165. Eliminate Answer B
There's only one answer left....
A
Question: A tester rejects 0.08% of the meters as defective, How many meters he tested to reject 2 meters ?
A.1200
B.2400
C.1400
D.2500
Answer: D.2500
Explanation: Explanation :
It means that 0.08% of x = 2
=>(8/100100x)=2
=>x=2100100/8
=>x=2500
Answer : D
Question: In a lottery, there are 12 prizes and 48 blanks. A lottery is drawn at random. What is the probability of getting a prize?
A.1/2
B.1/3
C.1/4
D.1/5
Answer: D.1/5
Explanation: P(winning a prize) = 12 / (12+48) = 12/60 = 1/5
The answer is D.