Mixture and Alligation questions concept with tricks

Mixture and Alligation based Questions

Question Type -1

In X gram mixture of milk and water, milk is P %. To make the quantity of milk in the mixture to be Q %, the quantity of milk added to the mixture will be.

Trick: X{(Q-P)/(100-Q)}

Ex. In a 60 liters mixture of milk and water, the quantity of milk is 5 %. In how much quantity, should milk be added to this mixture so that the quantity of milk in the mixture becomes 15 % ?

Ans. Use trick-
60*{(15-5)/(100-15)
60*(10/85)
120/17 liters

Question Type -2

In what ratio must a grocer mix two varieties of things costing Rs. C (Cheaper) and Rs. D(Costlier/Dearer) per kg respectively so as to get a mixture worth Rs. M kg?

Trick: (Cheaper quantity) : (Dearer quantity) = (D - M) : (M - C)

Ex. In what ratio must a grocer mix two varieties of pulses costing Rs. 15 and Rs. 20 per kg respectively so as to get a mixture worth Rs. 16.50 kg?

Ans. Use trick-
(Cheaper quantity) : (Dearer quantity) = (20-16.50):(16.50-15)
(Cheaper quantity) : (Dearer quantity) = (3.50):(1.50)
(Cheaper quantity) : (Dearer quantity) = 35:15
(Cheaper quantity) : (Dearer quantity) = 7:3