There are 85 brown and blue marbles in Box K. There are 57 brown and black marbles in Box L. The number of blue marbles in Box K is five times the number of black marbles in Box L. The number of brown marbles in both boxes is the same.
- How many black marbles are there in Box L?
- Find the total number of brown marbles in both boxes.
(a)
Number of blue marbles = 5 u
Number of black marbles = 1 u
Brown marbles + 5 u = 85 --- (1)
Brown marbles + 1 u = 57 --- (2)
(1) - (2)
5 u - 1 u = 85 - 57
4 u = 28
1 u = 28 ÷ 4 = 7
Number of black marbles
= 1 u
= 7
(b)
Number of brown marbles in Box L
= 57 - 7
= 50
Number of brown marbles in both boxes
= 2 x 50
= 100
Answer(s): (a) 7; (b) 100