A consumer spends all of her income(Y) on two goods Z and B.The price of good B

Question:

A consumer spends all of her income(Y) on two goods Z and B.The price of good B (PB) is $6. The Marginal Rate of Transformation MRT is equal to −2. That is 2 units of good B can be traded for 1 unit of good Z.This consumer is able to buy 18 units of good Z and 0 units of good B with his/her income. What is this consumer's level of income?
The consumer's income is $ ( )(round your answer to the nearest penny).