1212Johnny spends of his income on food, of his income on gas, and of his income on rent. What percentage of his income remains after he has paid for food, gas, and rent?

1212Begin by finding the common denominator of the three: . Johnny's total income can then be written as . The cost of food can be written as , the cost of gas can be written as , and the cost of rent can be written as .
Subtracting each of these costs from his total income yields: , which represents the amount of money he has left after paying for all three.
To find the percentage, divide 214 by 560 and multiply by 100: