You have 2.50. 3 times 10 is 30, so now you have 2.20. he bought twice as many six cent stamps as ten cent stamps. multiples of six that are applicable are 30, 60, 90, 120. six goes into 30 five times. Five can't be divided in half. six goes into 60 ten times. ten divided in half is five. fifty plus sixty, is only 110. six goes into ninety 15 times. fifteen can not be divided in half. six goes into 120 twenty times. 20 divided in half is ten. ten times ten is 100. 100 + 120 = 220. He bought 10 10cent stamps
