How many kgs. of wheat costing Rs. 5 per kg must be mixed with 45 kg of rice costing Rs. 6.40 per kg so that 20% gain may be obtained by selling the mixture at Rs. 7.20 per kg ?
Choose the correct choice from the following options.
A) 18
B) 99
C) 77
D) 26
E) 11
If the selling price of the mixture is Rs.7.2 when sold at 20% profit then   CP ×120100×120100 = 7.2 ⇒⇒ CP = Rs.6   Now by applying weighted average formula = K×5+45×6.4K+45=6K×5+45×6.4K+45=6   ⇒⇒ K = 18 kgs   18nswer:18
<result>A</result>
How many kgs. of wheat costing Rs. 5 per kg must be mixed with 45 kg of rice costing Rs. 6.40 per kg so that 20% gain may be obtained by selling the mixture at Rs. 7.20 per kg ?