Task: Question Answering
Input (English): Question: 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 ?

 Option A: 18

 Option B: 99

 Option C: 77

 Option D: 26

 Option E: 11
Output (English): Option A