Shannon had some chocolate bars. She sold 40% of her chocolate bars and gave half of the remainder to her cousin. After that, she bought 23 chocolate bars and had a total of 53 chocolate bars in the end. How many chocolate bars did Shannon have at first?
Percentage of chocolate bars that Shannon left after selling 405 of her chocolate bars
= 100% - 40%
= 60%

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

Number of chocolate bars that Shannon had left = 3 u

Number of chocolate bars that Shannon had in the end = 3 u + 23

3 u + 23 = 53
3 u = 53 - 23
3 u = 30

1 u = 30 ÷ 3 = 10

Total number of chocolate bars that Shannon had at first
= 10 u
= 10 x 10
= 100

Answer(s): 100