Raeann had some chocolate bars. She sold 40% of her chocolate bars and gave half of the remainder to her cousin. After that, she bought 42 chocolate bars and had a total of 66 chocolate bars in the end. How many chocolate bars did Raeann have at first?
Percentage of chocolate bars that Raeann left after selling 405 of her chocolate bars
= 100% - 40%
= 60%

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

Number of chocolate bars that Raeann had left = 3 u

Number of chocolate bars that Raeann had in the end = 3 u + 42

3 u + 42 = 66
3 u = 66 - 42
3 u = 24

1 u = 24 ÷ 3 = 8

Total number of chocolate bars that Raeann had at first
= 10 u
= 10 x 8
= 80

Answer(s): 80