6500+ Quantitative Aptitude Questions and Answers With Explanation

Q:

A man went downstream for 28 km in a motor boat and immediately returned. It took the man twice as long to make the return trip. If the speed of the river flow were twice as high, the trip downstream and back would take 672 minutes. Find the speed of the boat in still water and the speed of the river flow.

A) 12 km/hr, 3 km/hr	B) 9 km/hr, 3 km/hr
C) 8 km/hr, 2 km/hr	D) 9 km/hr, 6 km/hr

Answer & Explanation Answer: B) 9 km/hr, 3 km/hr

Explanation:

Let the speed of the boat = p kmph

Let the speed of the river flow = q kmph

From the given data,

$2 x \frac{28}{p + q} = \frac{28}{p - q}$

=> 56p - 56q -28p - 28q = 0

=> 28p = 84q

=> p = 3q.

Now, given that if

$\frac{28}{3 q + 2 q} + \frac{28}{3 q - 2 q} = \frac{672}{60} = > \frac{28}{5 q} + \frac{28}{q} = \frac{672}{60} = > q = 3 kmph = > x = 3 q = 9 kmph$

Hence, the speed of the boat = p kmph = 9 kmph and the speed of the river flow = q kmph = 3 kmph.

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

80 29608

Q:

A, B and C enter into a partnership. They invest Rs. 40,000, Rs. 80,000 and Rs. 1,20,000 respectively. At the end of the first year, B withdraws Rs. 40,000, while at the end of the second year, C withdraws Rs. 80,000. In what ratio will the profit be shared at the end of 3 years ?

A) 2 : 3 : 5	B) 3 : 4 : 7
C) 5 : 6 : 4	D) 1 : 3 : 5

Answer & Explanation Answer: B) 3 : 4 : 7

Explanation:

A : B : C = (40000 x 36) : (80000 x 12 + 40000 x 24) : (120000 x 24 + 40000 x 12)

= 144 : 192 : 336

= 3 : 4 : 7.

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Filed Under: Partnership

29 29607

Q:

The surface area of a cube is 1734 sq. cm. Find its volume

A) 2334 cubic.cm	B) 3356 cubic.cm
C) 4913 cubic.cm	D) 3478 cubic.cm

Answer & Explanation Answer: C) 4913 cubic.cm

Explanation:

Let the edge of the cube bea. Then,

6 $a^{2}$ = 1734

=> a = 17 cm.

Volume = $a^{3}$ = $17^{3}$ = 4193 cu.cm

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Filed Under: Volume and Surface Area

56 29604

Q:

The captain of a cricket team of 11 members is 26 years old and the wicket keeper is 3 years older. If the ages of these two are excluded, the average age of the remaining players is one year less than the average age of the whole team. What is the average age of the team ?

A) 20 years	B) 21 years
C) 23 years	D) 25 years

Answer & Explanation Answer: C) 23 years

Explanation:

Let the average age of the whole team be x years.

11x - (26 + 29) = 9 (x - 1)

=> 11x - 9x = 46

=> 2x = 46

=> x = 23.

So, average age of the team is 23 years.

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Filed Under: Average

57 29556

Q:

A sum of money becomes 7/6 of itself in 3 years at a certain rate of simple interest. The rate per annum is ?

A) 45/7 %	B) 50/9 %
C) 51/7 %	D) 47/ 9 %

Answer & Explanation Answer: B) 50/9 %

Explanation:

Let sum = S. Then, amount = 7S/6

S.I. = 7S/6 - S = S/6; Time = 3 years.

Rate = (100 x S) / (S x 6 x 3) = 5 5/9 = 50/9 %.

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

27 29550

Q:

Select the figure that does not belong in the following group.

A) D	B) B
C) C	D) A

Answer & Explanation Answer: C) C

Explanation:

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Filed Under: Odd Man Out
Exam Prep: Bank Exams

2 29550

Q:

3 pumps working 8 hours a day, can empty a tank in 2 days. How many hours a day must 4 pumps work to empty the tank in 1 day?

A) 9	B) 10
C) 11	D) 12

Answer & Explanation Answer: D) 12

Explanation:

Let the required no of working hours per day be x.

More pumps , Less working hours per day (Indirect Proportion)

Less days, More working hours per day (Indirect Proportion)

$\begin{array}{r} \begin{matrix} P u m p s & 4 : 3 \end{matrix} \\ \begin{matrix} D a y s & 1 : 2 \end{matrix} \end{array}\} ⋮ ⋮ 8 : x$

=> (4 * 1 * x) = (3 * 2 * 8)

=> x=12

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Filed Under: Chain Rule

47 29489

Q:

A speaks truth in 75% of cases and B in 80% of cases. In what percentage of cases are they likely to contradict each other, narrating the same incident

A) 30/100	B) 35/100
C) 45/100	D) 50/100

Answer & Explanation Answer: B) 35/100

Explanation:

Let A = Event that A speaks the truth

B = Event that B speaks the truth

Then P(A) = 75/100 = 3/4

P(B) = 80/100 = 4/5

P(A-lie) = $1 - \frac{3}{4}$ = 1/4

P(B-lie) = $1 - \frac{4}{5}$ = 1/5

Now, A and B contradict each other =[A lies and B true] or [B true and B lies]

= P(A).P(B-lie) + P(A-lie).P(B)

= $(\frac{3}{5} * \frac{1}{5}) + (\frac{1}{4} * \frac{4}{5}) = \frac{7}{20}$

= $(\frac{7}{20} * 100)$ = 35%

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Filed Under: Probability

64 29472

Quantitative Aptitude - Arithmetic Ability Questions

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