PSLE
Lynn had rubber duckies for sale. In the morning, she sold ¹₅ of the rubber duckies. In the afternoon, she sold ³₁₀ of the remaining rubber duckies. After that, there were 56 rubber duckies left. How many rubber duckies did Lynn have at first?
Fraction of rubber duckies left after selling in the morning
= 1 - ¹₅
= ⁴₅

Fraction of the remaining rubber duckies after selling in the afternoon
= 1 - ³₁₀
= ⁷₁₀

⁷₁₀ of remaining rubber duckies = 56
¹₁₀ of remaining rubber duckies = 56 ÷ 7 = 8
¹⁰₁₀ of remaining rubber duckies = 10 x 8 = 80

⁴₅ of total rubber duckies = 80
¹₅ of the total rubber duckies = 80 ÷ 4 = 20
⁵₅ of the total rubber duckies = 5 x 20 = 100

Number of rubber duckies at first = 100

Answer(s): 100