There are 57 black and purple marbles in Box A. There are 37 black and red marbles in Box B. The number of purple marbles in Box A is three times the number of red marbles in Box B. The number of black marbles in both boxes is the same.
- How many red marbles are there in Box B?
- Find the total number of black marbles in both boxes.
(a)
Number of purple marbles = 3 u
Number of red marbles = 1 u
Black marbles + 3 u = 57 --- (1)
Black marbles + 1 u = 37 --- (2)
(1) - (2)
3 u - 1 u = 57 - 37
2 u = 20
1 u = 20 ÷ 2 = 10
Number of red marbles
= 1 u
= 10
(b)
Number of black marbles in Box B
= 37 - 10
= 27
Number of black marbles in both boxes
= 2 x 27
= 54
Answer(s): (a) 10; (b) 54