Harry gave ¹₇ of his stamps to Jenson, ¹₆ of his remaining stamps to Zeph and ¹₃ of the rest of his stamps to Julian. He then had 10 stamps left. How many stamps had he at first?
Fraction of the rest of the stamps that Harry had left after giving to Jenson, Zeph and Julian
= 1 - ¹₃
= ²₃

²₃ of the rest of the stamps that Harry had left = 10
¹₃ of the rest of the stamps that Harry had left = 10 ÷ 2 = 5
³₃ of the rest of the stamps that Harry had left = 3 x 5 = 15

Fraction of his remaining stamps that Harry had left after giving to Jenson and Zeph
= 1 - ¹₆
= ⁵₆

⁵₆ of his remaining stamps that Harry had left = 15
¹₆ of his remaining stamps that Harry had left = 15 ÷ 5 = 3
⁶₆ of his remaining stamps that Harry had left = 6 x 3 = 18

Fraction of his remaining stamps that Harry had left after giving to Jenson
= 1 - ¹₇
= ⁶₇

⁶₇ of the stamps that Harry had left = 18
¹₇ of the stamps that Harry had left = 18 ÷ 6 = 3
⁷₇ of the stamps that Harry had left = 7 x 3 = 21

Number of stamps that Harry had at first = 21

Answer(s): 21