# Ratio and Proportion ( 16 to 20 )

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Ratio and Proportion ( 16 to 20 ):

# APTITUDE QUESTIONS (RATIO AND PROPORTION):

16. An amount of Rs.1230 is divided among A, B and C such that if their shares be reduced by Rs.5, Rs.10 and Rs.15 respectively, the remainders shall be in the ratio of 3:4:5. Then, B’s share was:

A)    Rs. 605

B)    Rs. 590

C)    Rs. 400

D)    Rs.410

E)    None of these

Explanation:

Remainder = Rs. [1230 – (5 + 10 + 15)] = Rs. 1200
∴ B’s share = Rs. (1200 * 4/12) + 10 = Rs.400

17. 15 litres of mixture contains 20% of alcohol and the rest water. If we mix 5 litres of water with it, than the percentage of alcohol in the new mixture would be:

A)    15%

B)    16(2/3)%

C)    17%

D)    18(1/2)%

E)    None of these

Explanation:

Alcohol in 15 litres of mix. = 20% of 15 litres = (20/100 * 15) = 3 litres
Water in it = (15 – 3) = 12 litres.
New quantity of mix. = (15 + 5) = 20 litres.
Quantity of alcohol in it = 3 litres.
Percentage of alcohol in new mix. = (3/20 * 100)% = 15%

18. The ages of A and B are in the ratio 3:1. Fifteen years hence, the ratio will be 2:1. Their present ages are:

A)    30 years, 10 years

B)    45 years, 15 years

C)    21 years, 7 years

D)    60 years, 20 years

E)    None of these

Explanation:

Suppose, ages of A and B be 3x years and x years respectively.
Then, (3x+15)/(x+15) = 2/1 <=> 2x + 30 = 3x + 15 <=> x = 15
Then, A’s age = (3 * 15) years = 45 years and B’s age = 15 years.

19. In a college, the ratio of the number of boys to girls is 8:5. If there are 150 girls, the total number of students in the college is:

A)    100

B)    250

C)    260

D)    390

E)    None of these

Explanation:

Let us consider that the number of boys and girls be 8x and 5x respectively. Then 5x = 150  x = 30
∴ Total number of students = 13x = (13 * 30) = 390

20. The sides of a triangle are in the ratio 1/2 : 1/3 : 1/4 and its perimeter is 104 cm. The length of the longest side is:

A)    52 cm

B)    48 cm

C)    32 cm

D)    26 cm

E)    None of these