PSLE
Opal had jigsaw puzzles for sale. In the morning, she sold ¹₅ of the jigsaw puzzles. In the afternoon, she sold ²₉ of the remaining jigsaw puzzles. After that, there were 56 jigsaw puzzles left. How many jigsaw puzzles did Opal have at first?
Fraction of jigsaw puzzles left after selling in the morning
= 1 - ¹₅
= ⁴₅

Fraction of the remaining jigsaw puzzles after selling in the afternoon
= 1 - ²₉
= ⁷₉

⁷₉ of remaining jigsaw puzzles = 56
¹₉ of remaining jigsaw puzzles = 56 ÷ 7 = 8
⁹₉ of remaining jigsaw puzzles = 9 x 8 = 72

⁴₅ of total jigsaw puzzles = 72
¹₅ of the total jigsaw puzzles = 72 ÷ 4 = 18
⁵₅ of the total jigsaw puzzles = 5 x 18 = 90

Number of jigsaw puzzles at first = 90

Answer(s): 90