6500+ Quantitative Aptitude Questions and Answers With Explanation

Q:

The ratio between the speeds of two trains is 7: 8. If the second train runs 400 kms in 4 hours, then the speed of the first train is ?

A) 83.5 km/hr	B) 84.5 km/hr
C) 86.5 km/hr	D) 87.5 km/hr

Answer & Explanation Answer: D) 87.5 km/hr

Explanation:

Let the speeds of two trains be 7X and 8X km/hr.

8x = 400/4

=> x= 12.5 km/hrX=4004=>X=12.5Km/hr

So speed of first train is 12.5*7 = 87.5 km/hr

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Filed Under: Time and Distance

63 34203

Q:

The diluted wine contains only 8 liters of wine and the rest is water. A new mixture whose concentration is 30%, is to be formed by replacing wine. How many liters of mixture shall be replaced with pure wine if there was initially 32 liters of water in the mixture ?

A) 4	B) 5
C) 8	D) None of these

Answer & Explanation Answer: B) 5

Explanation:

Wine Water

8L 32L

1 : 4

20 % 80% (original ratio)

30 % 70% (required ratio)

In ths case, the percentage of water being reduced when the mixture is being replaced with wine.

so the ratio of left quantity to the initial quantity is 7:8

Therefore , $\frac{7}{8} = [1 - \frac{K}{40}]$

=> K = 5 Lit

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Filed Under: Alligation or Mixture
Exam Prep: CAT , Bank Exams
Job Role: Bank PO , Bank Clerk

94 34155

Q:

Out of 9 persons, 8 persons spent Rs. 30 each for their meals. The ninth one spent Rs. 20 more than the average expenditure of all the nine. The total money spent by all of them was :

A) Rs. 292.50	B) Rs. 297.50
C) Rs. 298	D) Rs. 298.50

Answer & Explanation Answer: A) Rs. 292.50

Explanation:

Let the average expenditure be Rs. x Then,

9x=[(8*30)+(x+20)]<=>9x =x+260 <=> x =32.50

Total money spent = 9x = Rs. (9 x 32.5O) = Rs 292. 50

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Filed Under: Average

95 34088

Q:

The diagonal of a rectangle is $\sqrt{41}$ cm and its area is 20 sq. cm. The perimeter of the rectangle must be:

A) 18	B) 28
C) 38	D) 48

Answer & Explanation Answer: A) 18

Explanation:

$\sqrt{(l^{2} + b^{2})} = \sqrt{41}$ (or) $l^{2} + b^{2} = 41$

Also, $l b = 20$

${(l + b)}^{2} = l^{2 +} b^{2} + 2 l b$ = 41 + 40 = 81

(l + b) = 9.

Perimeter = 2(l + b) = 18 cm.

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

129 34070

Q:

When 0.36 is written in simplest form, the sum of the numerator and the denominator is :

A) 15	B) 34
C) 64	D) 13

Answer & Explanation Answer: B) 34

Explanation:

0.36 = 36/100 = 9/25.

Sum of the numerator and denominator is 9 + 25 = 34

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Filed Under: Decimal Fractions

76 34041

Q:

The average age of 36 students in a group is 14 years. When teacher's age is included to it, the average increases by one. What is the teacher's age in years ?

A) 35 years	B) 45 years
C) 51 years	D) 54 years

Answer & Explanation Answer: C) 51 years

Explanation:

Age of the teacher = (37 * 15 - 36 * 14) years = 51 years.

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Filed Under: Average

28 34030

Q:

A works twice as fast as B.If B can complete a work in 18 days independently,the number of days in which A and B can together finish the work is:

A) 4 days	B) 6 days
C) 8 days	D) 10 days

Answer & Explanation Answer: B) 6 days

Explanation:

Ratio of rates of working of A and B =2:1. So, ratio of times taken =1:2

Therefore, A's 1 day's work=1/9

B's 1 day's work=1/18

(A+B)'s 1 day's work= 1/9 + 1/18 = 1/6

so, A and B together can finish the work in 6 days

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Filed Under: Time and Work

101 33949

Q:

Two brother X and Y appeared for an exam. The probability of selection of X is 1/7 and that of B is 2/9. Find the probability that both of them are selected.

A) 1/63	B) 1/14
C) 2/63	D) 1/9

Answer & Explanation Answer: C) 2/63

Explanation:

Let A be the event that X is selected and B is the event that Y is selected.

P(A) = 1/7, P(B) = 2/9.

Let C be the event that both are selected.

P(C) = P(A) × P(B) as A and B are independent events:

= (1/7) × (2/9) = 2/63

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Filed Under: Probability

30 33787

Quantitative Aptitude - Arithmetic Ability Questions

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