Question 16
Xiaoming wants to buy school supplies. The total number of pens, pencils and erasers that he wants to buy is 100. The price of one pen is 6 yuan, one pencil is 4 yuan and one eraser is 1 yuan. He spends exactly 200 yuan and buys at least one of each type. How many different combinations of the number of pens, pencils and erasers can he buy?