John gave ¹₈ of his buttons to Eric, ²₇ of his remaining buttons to Ken and ¹₃ of the rest of his buttons to Ian. He then had 110 buttons left. How many buttons had he at first?
Fraction of the rest of the buttons that John had left after giving to Eric, Ken and Ian
= 1 - ¹₃
= ²₃

²₃ of the rest of the buttons that John had left = 110
¹₃ of the rest of the buttons that John had left = 110 ÷ 2 = 55
³₃ of the rest of the buttons that John had left = 3 x 55 = 165

Fraction of his remaining buttons that John had left after giving to Eric and Ken
= 1 - ²₇
= ⁵₇

⁵₇ of his remaining buttons that John had left = 165
¹₇ of his remaining buttons that John had left = 165 ÷ 5 = 33
⁷₇ of his remaining buttons that John had left = 7 x 33 = 231

Fraction of his remaining buttons that John had left after giving to Eric
= 1 - ¹₈
= ⁷₈

⁷₈ of the buttons that John had left = 231
¹₈ of the buttons that John had left = 231 ÷ 7 = 33
⁸₈ of the buttons that John had left = 8 x 33 = 264

Number of buttons that John had at first = 264

Answer(s): 264