Adam has some stickers
He gives away ¹₃ and an additional 20 stickers to Bryan.
He gives away ²₇ of the remainder and 25 more stickers to Chris
and ²₅ of the rest to David.
Adam has 15 stickers left.
How many stickers does he have at first?
Number of stickers that Adam gives to Bryan = ¹₃ of the total + 20
Number of stickers that Adam gives to Chris = ²₇ of the remainder + 25
Number of stickers that Adam gives to David = ²₅ of the rest
Number of stickers left = 15


Working backwards.
1 - ²₅ = ³₅

³₅ of the rest → 15
¹₅ of the rest → 15 ÷ 3 = 5
⁵₅ of the rest → 5 x 5 = 25

1 - ²₇ = ⁵₇

⁵₇ of the remainder = 25 + 25 = 50
¹₇ of the remainder = 50 ÷ 5 = 10
⁷₇ of the remainder = 7 x 10 = 70

1 - ¹₃ = ²₃
²₃ of the total = 70 + 20 = 90
¹₃ of the total = 90 ÷ 2 = 45
³₃ of the total = 3 x 45 = 135

Number of stickers at first = 135

Answer(s): 135