There are 71 purple and blue marbles in Box V. There are 50 purple and grey marbles in Box W. The number of blue marbles in Box V is four times the number of grey marbles in Box W. The number of purple marbles in both boxes is the same.
- How many grey marbles are there in Box W?
- Find the total number of purple marbles in both boxes.
(a)
Number of blue marbles = 4 u
Number of grey marbles = 1 u
Purple marbles + 4 u = 71 --- (1)
Purple marbles + 1 u = 50 --- (2)
(1) - (2)
4 u - 1 u = 71 - 50
3 u = 21
1 u = 21 ÷ 3 = 7
Number of grey marbles
= 1 u
= 7
(b)
Number of purple marbles in Box W
= 50 - 7
= 43
Number of purple marbles in both boxes
= 2 x 43
= 86
Answer(s): (a) 7; (b) 86