Robert buys a pair of pants and a shirt for a certain price .The shirt accounts for 2/5 of the total price of both items. He pays $36 for the pair of pants. If Robert gives the cashier $100, how much change will he receive after buying the pants and the shirt?
$36 is the cost of pants, which accounts for (1-2/5)=3/5 of the total cost.
So the total cost is
36รท(3/5)=60
If there are no sales taxes, he should get 100-60=$40 in change.