# Ratio and Proportion ( 11 to 15 )

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Ratio and Proportion ( 11 to 15 ):

# APTITUDE QUESTIONS (RATIO AND PROPORTION):

11. Two whole numbers whose sum is 72 cannot be in the ratio:

A)    5 : 7

B)    3 : 5

C)    3 : 4

D)    4 : 5

E)    None of these

Explanation:

The sum of the ratio must divide 72. So, the ratio cannot be 3:4.

12. If 40% of a number is equal to two-third of another number, what is the ratio of first number to the second number?

A)    2:5

B)    3:7

C)    5:3

D)    7:3

E)    None of these

Explanation:

Let 40% of A = (2/3)B.
Then, 40A/100 = 2B/3  2A/5 = 2B/3 <=> A/B = (2/3 * 5/2) = 5/3
∴ A : B = 5 : 3

13. What least number must be subtracted from each of the numbers 14, 17, 34 and 42 so that the remainders may be proportional?

A)    0

B)    1

C)    2

D)    7

E)    None of these

Explanation:

Let the required number be x. Then, (14 – x) : (17 – x) : : (34 – x) : (42 – x)
∴ (14-x/17-x) = (34-x/42-x) <=> (14 – x) (42 – x) = (17 – x) (34 – x)
 <=> x2 – 56x + 588 = x2 – 51x + 578  5x = 10  x = 2
∴ required number = 2

14. The fourth proportional to 5, 8, 15 is:

A)    18

B)    24

C)    19

D)    20

E) None of these

Explanation:

Let us consider fourth proportional 5, 8, 15 be x.
Then, 5 : 8 : : 15 : x <=> 5x = (8 * 15) <=> x = 8 * 15/5 = 24

15. The prices of a scooter and a T.V. are in the ratio 7 : 5. If the scooter costs Rs.8000 more than T.V. set, then the price of a T.V. set is:

A)    Rs. 20000

B)    Rs. 24000

C)    Rs. 28000

D)    Rs. 32000

E)    None of these

Explanation:

Let the prices of a scooter and a T.V. set be Rs. 7x and Rs. 5x respectively.
Then, 7x – 5x = 8000 <=> 2x = 8000  x = 4000
∴ Price of a T.V. set = Rs.(7 * 4000) = Rs.28000