Alligation & Mixtures Model Questions Set 1 Practice Questions Answers Test with Solutions & More Shortcuts

Question : 6

In what ratio must tea at Rs. 62 per kg be mixed with tea at Rs. 72 per kg so that the mixture must be worth Rs. 64.50 per kg?

a) 3 : 2

b) 5 : 3

c) 3 : 1

d) 4 : 3

e) None of these

Answer: (c)

By the rule of alligation:

∴ Required ratio = 750 : 250 = 3 : 1.

Question : 7

Jayashree purchased 150 kg of wheat of the rate of Rs. 7 per kg. She sold 50 kg at a profit of 10%. At what rate per kg should she sell the remaining to get a profit of 20% on the total deal?

a) 8.75

b) 9.75

c) 6.50

d) 7.50

e) None of these

Question : 8

In what ratio should milk and water be mixed so that after selling the mixture at the cost price a profit of 2 16 % 3 is made?

a) 1 : 6

b) 2 : 5

c) 1 : 2

d) 2 : 3

e) None of these

Question : 9

A dishonest milkman professes to sell his milk at cost price but he mixes it with water and thereby gains 25%. The percentage of water in the mixture is ___________.

a) 15%

b) 25%

c) 10%

d) 20%

e) None of these

Answer: (b)

We will apply alligaton on % profit. If he sells the milk at CP,

he gains 0%. But if he sells water at CP, he gains 100%.

Ratio of milk to water in the mixture should be 3 : 1

∴ % of water in mixture = $1/{3 + 1}$ × 100 = 25%

Question : 10

A can contains a mixture of two liquids A and B in proportion 7 : 5. When 9 litres of mixture are drawn off and the can is filled with B, the proportion of A and B becomes 7 : 9. How many litres of liquid A was contained by the can initially?

a) 21 l

b) 36 l

c) 20 l

d) 30 l

e) None of these

Answer: (b)

Apply alligation on fraction of A in each mixture.

Ratio of original mixture to B = $7/{16} : 7/{48}$ = 3 : 1

When 9 litres of B is mixed, original mixture should be $9/1$ × 3

= 27 litres.

Therefore initial quantity in can = 27 + 9 = 36 litres.