Joelle had some chocolate bars. She sold 40% of her chocolate bars and gave half of the remainder to her brother. After that, she bought 24 chocolate bars and had a total of 57 chocolate bars in the end. How many chocolate bars did Joelle have at first?
Percentage of chocolate bars that Joelle left after selling 405 of her chocolate bars
= 100% - 40%
= 60%

Fraction of chocolate bars that Joelle had left after giving to her brother
= ¹₂ x 60%
= ³₁₀

Number of chocolate bars that Joelle had left = 3 u

Number of chocolate bars that Joelle had in the end = 3 u + 24

3 u + 24 = 57
3 u = 57 - 24
3 u = 33

1 u = 33 ÷ 3 = 11

Total number of chocolate bars that Joelle had at first
= 10 u
= 10 x 11
= 110

Answer(s): 110