Mary has $50.00. She goes to the mall and buys lipstick and then shampoo, which is half the price of.......?

the lipstick. She spends half of what she left on lunch, leaving her with $15.00. What was the cost of the shampoo?Mary has $50.00. She goes to the mall and buys lipstick and then shampoo, which is half the price of.......?
6.50