Total amount, T = $100 million.
Cost of wheat per ton, C = $300 .
Price per fighter plane, c = $15 million.
Now,
Price of 5 fighter planes, P = $( 15 × 5 ) = $75 million.
Amount left = $( 100 - 75 ) = $25 million.
So,
Number of tons of wheat government can buy is :
Therefore, number of tons of wheat the government can afford is 83333.33 tons.
Hence, this is the required solution.