There are 54 black and white marbles in Box Y. There are 45 black and green marbles in Box Z. The number of white marbles in Box Y is four times the number of green marbles in Box Z. The number of black marbles in both boxes is the same.
- How many green marbles are there in Box Z?
- Find the total number of black marbles in both boxes.
(a)
Number of white marbles = 4 u
Number of green marbles = 1 u
Black marbles + 4 u = 54 --- (1)
Black marbles + 1 u = 45 --- (2)
(1) - (2)
4 u - 1 u = 54 - 45
3 u = 9
1 u = 9 ÷ 3 = 3
Number of green marbles
= 1 u
= 3
(b)
Number of black marbles in Box Z
= 45 - 3
= 42
Number of black marbles in both boxes
= 2 x 42
= 84
Answer(s): (a) 3; (b) 84