One quantity of wheat at Rs 9.30 per Kg is mixed with another quality at a certain rate in the ratio 8 : 7. If the mixture so formed be worth Rs 10 per Kg, what is the rate per Kg of the second quality of wheat?

Answer: Option B

Let the rate of second quality be Rs. x per Kg.
C.P of 1 Kg wheat of 1st kind = 930 p
C.P of 1 Kg wheat of 2nd kind = 100x p
Mean price = 1000 p
By rule of alligation we have required ratio 8 : 7
930 x / (Mean Price) (1000) / (x-10) : 0.7
So we get required ratio, (x-10) : 0.7 :: 8 : 7
⇒ x = 10.80 per Kg