6500+ Quantitative Aptitude Questions and Answers With Explanation

Q:

Two pipes A and B can fill a tank in 24 hours and $17 \frac{1}{7}$ hours respectively. Harihar opened the pipes A and B to fill an empty tank and some times later he closed the taps A and B , when the tank was supposed to be full. After that it was found that the tank was emptied in 2.5 hours because an outlet pipe "C" connected to the tank was open from the beginning. If Harihar closed the pipe C instead of closing pipes A and B the remaining tank would have been filled in :

A) 2 hours	B) 8 hours
C) 6 hours	D) 4 hours

Answer & Explanation Answer: B) 8 hours

Explanation:

Efficiency of Inlet pipe A = 4.16% $(\frac{100}{24})$

Efficiency of Inlet pipe B = 5.83% $(\frac{100}{17 \frac{1}{7}})$

Therefore, Efficiency of A and B together = 100 %

Now, if the efficiency of outlet pipe be x% then in 10 hours the capacity of tank which will be filled = 10 * (10 - x)

Now, since this amount of water is being emptied by 'C' at x% per hour, then

$\frac{10 x (10 - x)}{x} = 2.5 h r s$

=> x = 8

Therefore, in 10 hours 20% tank is filled only. Hence, the remaining 80% of the capacity will be filled by pipes A and B in 80/10 = 8 hours

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Filed Under: Time and Work
Exam Prep: AIEEE , Bank Exams , CAT
Job Role: Bank Clerk , Bank PO

38 17720

Q:

From the 50 liters of milk, 5 liters of milk is taken out and after it 5 liters of water is added to the rest amount of milk. Again 5 liters of milk and water is drawn out and it was replaced by 5 liters of water. If this process is continued similarly for the third time, the amount of milk left after the third replacement:

A) 45L	B) 36.45L
C) 40.5L	D) 42.5L

Answer & Explanation Answer: B) 36.45L

Explanation:

General Formula:

Final or reduced concentration = initial concentration x ${(1 - \frac{a m o u n t b e i n g r e p l a c e d i n e a c h o p e r a t i o n}{t o t a l a m o u n t})}^{n}$

where n is the number of times the same operation is being repeated. The "amount being replaced" could be pure or mixture as per the case. similarly ,"total amount" could also be either pure or mixture. Here amount being replaced denotes the quantity which is to be withdrawn in each time.

Therefore, $50 \times {(1 - \frac{5}{50})}^{3}$

= 36.45 L

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Filed Under: Alligation or Mixture

20 17705

Q:

In an NGO the daily average wages of 20 illiterate employees is decreased from Rs.25 to Rs.10, thus the average salary of all the literate and illiterate employees is decreased Rs.10 per day. The No. of educated employees working in the NGO is :

A) 15	B) 20
C) 10	D) Data Insufficient

Answer & Explanation Answer: C) 10

Explanation:

Total employees = $\frac{(25 - 10) \times 20}{10} = 30$

Hence number of educated employees = 30-20 = 10

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Filed Under: Average

32 17674

Q:

A car mechanic purchased four old cars for Rs. 1 lakh. He spent total 2 lakh in the maintenance and repairing of these four cars. what is the average sale price of the rest three cars to get 50% total profit if he has already sold one of the four cars at Rs. 1.2 lakh?

A) 1.5 lakh	B) 1.1 lakh
C) 1.2 lakh	D) 1.65 lakh

Answer & Explanation Answer: B) 1.1 lakh

Explanation:

Total cost of 4 cars = 1+2 = 3 lakh

Total S.P of 4 cars = 3 x 1.5 = 4.5 lakh ( $S i n c e S . P = \frac{(100 + G a i n %)}{100} x C . P$ )

S.P of 1 car = 1.2 lakh

S.P of rest 3 cars = 4.5 - 1.2 = 3.3 lakh

Average S.P of all the 3 cars = 1.1 lakh

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Filed Under: Profit and Loss
Exam Prep: AIEEE , Bank Exams , CAT
Job Role: Bank Clerk , Bank PO

64 17670

Q:

Given that on 9th August 2016 is Saturday. What was the day on 9th August 1616 ?

A) Saturday	B) Sunday
C) Friday	D) Monday

Answer & Explanation Answer: A) Saturday

Explanation:

We know that, After every 400 years, the same day occurs.

Thus, if 9th August 2016 is Saturday, before 400 years i.e., on 9th August 1616 has to be Saturday.

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Filed Under: Calendar
Exam Prep: GATE , CAT , Bank Exams , AIEEE
Job Role: Bank PO , Bank Clerk

70 17638

Q:

Two trains starting at the same time from two stations 200 km apart and going in opposite directions cross each other at a distance of 110 km from one of the stations. What is the ratio of their speeds?

A) 9 : 20	B) 11 : 9
C) 11 : 20	D) None of these

Answer & Explanation Answer: B) 11 : 9

Explanation:

In the same time, they cover 110 km and 90 km respectively.

Therefore, Ratio of their speeds = 110 : 90 = 11 : 9

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Filed Under: Time and Distance

18 17590

Q:

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 & Explanation Answer: D) 2 hrs

Explanation:

Speed in downstream = 96/8 = 12 kmph

Speed of current = 4 km/hr

Speed of the boatman in still water = 12 – 4 = 8 kmph

Speed in upstream = 8 – 4 = 4 kmph

Time taken to cover 8 km upstream = 8/4 = 2 hours.

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Filed Under: Boats and Streams
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Bank Clerk , Bank PO

18 17580

Q:

The simple interest on Rs. 25 for 4 months at the rate of 3 paise per rupee per month is :

A) 240 paise	B) Rs. 1.40
C) Rs. 2.20	D) Rs. 3

Answer & Explanation Answer: D) Rs. 3

Explanation:

I = PTR/100
I = 25 x 4 x 0.03/100
I = 0.03 x 100 = 300 Ps = Rs. 3

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Filed Under: Simple Interest
Exam Prep: AIEEE , Bank Exams , CAT , GATE
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24 17556

Quantitative Aptitude - Arithmetic Ability Questions

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