This set of Aptitude Questions and Answers (MCQs) focuses on “Ratio and Proportion – Set 3”.

1. A : b = 9 : 11, b : c = 9 : 11. Find a : c.

a) 81 : 121

b) 99 : 121

c) 91 : 81

d) 81 : 99

View Answer

Explanation: A : b = 9 : 11, b : c = 9 : 11

A : b : c = 9 * 9 : 11 * 9 : 11 * 11 = 81 : 99 : 121

A : c = 81 : 121

2. The ratio of two numbers is 8 : 9. Find their product if their sum is 187.

a) 8271

b) 8712

c) 8217

d) 8172

View Answer

Explanation: Let the numbers be in terms of x.

8 : 9 = 8x : 9x

8x + 9x = 187

17x = 187

X = 187/17 = 11

8x = 88, 9x = 99

88 * 99 = 8712

3. The ratio of ages of two brothers is 6 : 7. Find the age of the elder brother if at the time of the birth of younger brother the elder brother was 6 years old.

a) 36 years

b) 40 years

c) 42 years

d) 48 years

View Answer

Explanation: Let the ages be in terms of x.

6 : 7 = 6x : 7x

At the time of birth of the younger brother, the elder was 6 years old.

The difference between their ages = 6 years

7x – 6x = 6 years

X = 6 years

7x = 7 * 6 = 42 years

4. A mixture contains milk and water in a ratio 5 : 9. When 5 liters of water is added the ratio changes to 5 : 11. Find the quantity of milk in the initial mixture.

a) 11 liters

b) 11.5 liters

c) 12 liters

d) 12.5 liters

View Answer

Explanation: Let the quantities of milk and water be in terms of x.

The initial quantity of milk and water = 5 : 9 = 5x : 9x

The changed quantity of milk and water = 5 : 11 = 5x : 11x

On adding 5 liters of water the quantity of water changed from 9x to 11x

11x – 9x = 2x

2x = 5 liters of water

X = 2.5

The initial quantity of milk = 5x = 5 * 2.5 = 12.5 liters.

5. The ratio of gold and silver in a ring is 4 : 7. The ring costs 61100 rupees. Find the price of the gold in the ring if silver costs 1/10^{th} of gold.

a) 31050 rupees

b) 40000 rupees

c) 50000 rupees

d) 52000 rupees

View Answer

Explanation: Let the quantities of gold and silver in the ring be in terms of x.

The quantity of silver in the ring = 7x and the quantity of gold = 4x

The price of gold and silver are in a ratio 10 : 1

The total price of gold in the ring = 4x * 10 = 40x

The total price of silver in the ring = 7x * 1 = 7x

The total price of the ring = 61100 rupees

The part of gold in the price = 40x

47x = 61100

40x = 61100/47 * 40 = 52000 rupees

6. A mixture contains two liquids a and b in a ratio 9 : 16. Find the ratio of their prices if the mixture costs 175 rupees and the ratio of their prices in the mixture is 3 : 4.

a) 3 : 4

b) 4 : 3

c) 9 : 16

d) 16 : 9

View Answer

Explanation: Let the quantities in the liquid be in terms of x.

The quantity of liquid a is 9x and the quantity of liquid is 16x.

Their price in the liquid is in the ratio 3 : 4.

The price of liquid a in the liquid = 175/7 * 3 = 75 rupees

The price of liquid b in the liquid = 175/7 * 4 = 100 rupees

The quantity of liquid a = 9x

The price of liquid a is 75 rupees.

The price of liquid a for 1x.

X = 75/9 = 25/3

The quantity of liquid b in the mixture = 16x

The price of the liquid b in the mixture = 100 rupees

The price of liquid b for 1x

X = 100/16 = 25/4

The ratio of price of a and b = 25/3 : 25/4 = 100 : 75 = 4 : 3

7. The ratio of foam to cotton (by weight) in a mattress of 27 kg is 2 : 7. Find the price of cotton in the mattress if cotton is available at a price of 40 rupees per kg.

a) 840 rupees

b) 420 rupees

c) 210 rupees

d) 105 rupees

View Answer

Explanation: Let the weights of cotton and foam be in terms of x.

The weight of cotton = 7x and the weight of cotton is 2x.

The total weight = 9x = 27 kg

X = 3 kg

The weight of cotton = 7x = 21 kg

The price of cotton = 40 rupees / kg

The price of cotton in the mattress = 21 * 40 = 840 rupees

8. The ratio platinum to silver in a bracelet is 5 : 7. If the price of platinum is 1/10^{th} the price of silver, find the cost of the bracelet if the cost of platinum in the bracelet is 24000 rupees.

a) 360000

b) 350000

c) 340000

d) 320000

View Answer

Explanation: 5 parts of platinum in the bracelet costs 24000 rupees.

1 part of platinum will cost 24000/5 = 4800 rupees

1 part of platinum costs 4800 rupees.

Silver is 10 times as costly as platinum.

Price of silver per unit = 4800 * 10 = 48000

The amount of silver used = 7 units

The price of silver in the bracelet = 48000 * 7 = 336000

The price of platinum used in the bracelet = 24000

The price of the bracelet = 24000 + 336000 = 360000

9. The cost of 1 gram of silver is 200 rupees. The ratio of price of silver to gold is 1 : 15. What will be the price of a ring 12 grams in weight with gold to silver ratio 5 : 1?

a) 34000 rupees

b) 30400 rupees

c) 30040 rupees

d) 34040 rupees

View Answer

Explanation: The price of 1 gram of gold = 15 times the price if 1 gram of silver = 200 * 15 = 3000

The quantity of gold in the ring = 5 times that of silver

Let the quantities of gold and silver be in terms of x.

5x + x = 6x

6x = 12 grams

X = 2 grams

The quantity of gold in the ring = 5x = 10 grams

The price of silver in the ring = x = 2 grams

The price of gold in the ring = 10 * 3000 = 30000 rupees

The price of silver in the ring = 200 * 2 = 400 rupees

The price of the ring = 30000 + 400 rupees = 30400 rupees

10. The price of 17 grams of copper is 251 rupees. Find the price of 1241 grams of tin if the ratio of prices of tin to copper is 2 : 3.

a) 27484.5 rupees

b) 27848.5 rupees

c) 28474.5 rupees

d) 28474.5 rupees

View Answer

Explanation: The price of 17 grams of copper = 251 rupees

The price of 1 gram of copper = 251/17 rupees

The ratio of prices of copper to tin = 2 : 3

The price of I gram of tin = (251/17) / 2 * 3 = 753/34

The price of 1241 grams of tin = 1241 * 753/34 = 36.5 * 753 = 27484.5 rupees

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