Bobby had 60% fewer chocolate bars than Valen. After Valen gave 156 chocolate bars to Bobby, Bobby had ⁵₆ as many chocolate bars as Valen. How many chocolate bars did each of them have in the end?

1. Valen
2. Bobby

	Bobby	Valen	Total
Before	2x11 = 22 u	5x11 = 55 u	7x11 = 77 u
Change	+ 156	- 156
After	5x7 = 35 u	6x7 =  42 u	11x7 = 77 u

Number of chocolate bars that Bobby had at first in percentage
= 100% - 60%
= 40%

40% = ⁴⁰₁₀₀ = ²₅

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 11 and 7 is 77.

Number of chocolate bars that Valen gave to Bobby
= 55 u - 42 u
= 13 u

13 u = 156

1 u = 156 ÷ 13 = 12

Number of chocolate bars that Bobby had in the end
= 35 u
= 35 x 12
= 420

Number of chocolate bars that Valen had in the end
= 42 u
= 42 x 12
= 504

Answer(s): (a) 420; (b) 504