6500+ Quantitative Aptitude Questions and Answers With Explanation

Q:

9 men and 12 boys finish a job in 12 days, 12 men and 12 boys finish it in 10 days. 10 men and 10 boys shall finish it in how many days ?

A) 15 days	B) 11 days
C) 14 days	D) 12 days

Answer & Explanation Answer: D) 12 days

Explanation:

9M + 12B ----- 12 days ...........(1)
12M + 12B ------- 10 days........(2)
10M + 10B -------?
108M + 144B = 120M +120B
24B = 12M => 1M = 2B............(3)

From (1) & (3)

18B + 12B = 30B ---- 12 days

20B + 10B = 30B -----? => 12 days.

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

22 23571

Q:

In a college, the ratio of the number of boys to girls is 8 : 5. If there are 160 girls, the total number of students in the college is

A) 100	B) 250
C) 260	D) 416

Answer & Explanation Answer: D) 416

Explanation:

Let the number of boys and girls be 8x and 5x.
Total number of students = 13x = 13 * 32 = 416.

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Filed Under: Ratios and Proportions

97 23561

Q:

A man wants to sell his scooter .There are two offers one at Rs12000 cash and other at a credit of Rs12880 to be paid after 8 months ,money being at 18% per annum which is better offer?

A) Rs.12880	B) Rs.12000
C) Both are equally good	D) None of the above

Answer & Explanation Answer: B) Rs.12000

Explanation:

PW of Rs.12,880 due 8 months hence

= Rs. [12880 x 100] / [100+(18 x 8/12)] =Rs.11500

Clearly 12000 in cash is a better offer.

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Filed Under: True Discount

12 23529

Q:

If the arithmetic mean of seventy-five numbers is calculated, it is 35. if each number is increased by 5, then mean of new numbers is :

A) 30	B) 40
C) 50	D) 60

Answer & Explanation Answer: B) 40

Explanation:

Let the numbers are $x_{1,} x_{2,} . . . . . . . x_{75}$

By Hypothesis , $\frac{x_{1} + x_{2} + . . . . x_{75}}{75} = 35$ ......(i)

Mean of new numbers = $\frac{(x_{1} + 5) + (x_{2} + 5) + . . . . . . . (x_{75} + 5)}{75}$

$\frac{x_{1} + x_{2} + . . . . . . x_{75} + 5 * 75}{75}$

$\frac{x_{1} + x_{2} + . . . . . . x_{75}}{75} + \frac{375}{75} = 35 + 5 = 40$ By (i)

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Filed Under: Average

43 23508

Q:

In a Plane there are 37 straight lines, of which 13 pass through the point A and 11 pass through the point B. Besides, no three lines pass through one point, no lines passes through both points A and B , and no two are parallel. Find the number of points of intersection of the straight lines.

A) 525	B) 535
C) 545	D) 555

Answer & Explanation Answer: B) 535

Explanation:

The number of points of intersection of 37 lines is $C_{2}^{37}$ . But 13 straight lines out of the given 37 straight lines pass through the same point A.

Therefore instead of getting $C_{2}^{13}$ points, we get only one point A. Similarly 11 straight lines out of the given 37 straight lines intersect at point B. Therefore instead of getting $C_{2}^{11}$ points, we get only one point B.

Hence the number of intersection points of the lines is $C_{2}^{37} - C_{2}^{13} - C_{2}^{11} + 2$ = 535

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Filed Under: Permutations and Combinations
Exam Prep: CAT , Bank Exams , AIEEE
Job Role: Bank PO , Bank Clerk

43 23501

Q:

Rahul went to purchase a Nokia mobile handset, the shopkeeper told him to pay 20% tax if he asked the bill. Rahul manages to get the discount of 5% on the actual saleprice of the mobile and he paid the shopkeeper Rs. 3325 without tax. Besides he manages to avoid to pay 20% tax on the already discounted price, what is the amount of discount that he has gotten?

A) 750	B) 375
C) 875	D) 525

Answer & Explanation Answer: C) 875

Explanation:

CP = 100, SP (with tax) =120

New SP = 100 - 5 = 95

Effective discount = 120 - 95 = 25

So, at SP of 95 ----> discount = 25

and at SP of 3325 -----> discount = $\frac{25}{95} \times 3325 = 875$

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

54 23495

Q:

The difference between the simple interest received from two different sources on Rs.1500 for 3 years is Rs.13.50. The difference between their rates of interest is

A) 0.1%	B) 0.2%
C) 0.3%	D) 0.4%

Answer & Explanation Answer: C) 0.3%

Explanation:

(1500 x R1 x 3)/100

=> 4500 (R1-R2) = 1350

=> (R1-R2)= 1350/4500 = 0.3 %

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Filed Under: Simple Interest
Exam Prep: GRE

48 23468

Q:

What is the value of (sin30° + 1/3) ?

A) (2√2+√3)/2	B) (√6+1)/√3
C) 7/3	D) 5/6

Quantitative Aptitude - Arithmetic Ability Questions

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