In equilibrium a consumer was buying 5 units of good A and some of good B. His income was Rs 100 and the prices were P A = Rs 8 and P B = Rs 5. The price of good A falls to Rs 5. By how much does his income need to be compensated so that he is able to buy the (old) bundle at the original equilibrium?

In equilibrium a consumer was buying 5 units of good A and some of
good B. His income was Rs 100 and the prices were P A = Rs 8 and P B = Rs 5. The
price of good A falls to Rs 5. By how much does his income need to be compensated so
that he is able to buy the (old) bundle at the original equilibrium?