In what ratio must a grocer mix two varieties of tea worth Rs. 60 a kg and Rs. 65 a kg so that by selling the mixture at Rs. 68.20 a kg he may gain 10%?
A. 3 : 2
B. 3 : 4
C. 3 : 5
D. 4 : 5
Answer: Option A
Solution (By Examveda Team)
S.P. of 1 kg of the mixture = Rs. 68.20, Gain = 10%C.P. of 1 kg of the mixture = Rs. $$\left( {\frac{{100}}{{110}} \times 68.20} \right)$$ = Rs. 62
By the rule of alligation, we have:

∴ Required ratio = 3 : 2

Given 110%=68.20
So 100%=X (assume)
After Cross multiplication we get X=62.
Now applying mixture concept
60 65
62
(65-62) (62-60)
=3 =2
There fore Ratio is =3:2