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%?

Answer: Option A

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