Andy had 75% fewer chocolate bars than Zane. After Zane gave 390 chocolate bars to Andy, Andy had ²₃ as many chocolate bars as Zane. How many chocolate bars did each of them have in the end?

1. Zane
2. Andy

	Andy	Zane	Total
Before	1x5 = 5 u	4x5 = 20 u	5x5 = 25 u
Change	+ 390	- 390
After	2x5 = 10 u	3x5 =  15 u	5x5 = 25 u

Number of chocolate bars that Andy had at first in percentage
= 100% - 75%
= 25%

25% = ²⁵₁₀₀ = ¹₄

The total number of chocolate bars at first and in the end remains unchanged. Make the total number of chocolate bars the same. LCM of 5 and 5 is 25.

Number of chocolate bars that Zane gave to Andy
= 20 u - 15 u
= 5 u

5 u = 390

1 u = 390 ÷ 5 = 78

Number of chocolate bars that Andy had in the end
= 10 u
= 10 x 78
= 780

Number of chocolate bars that Zane had in the end
= 15 u
= 15 x 78
= 1170

Answer(s): (a) 780; (b) 1170