There are 67 green and blue pens in Box C. There are 31 green and black pens in Box D. The number of blue pens in Box C is five times the number of black pens in Box D. The number of green pens in both boxes is the same.
- How many black pens are there in Box D?
- Find the total number of green pens in both boxes.
(a)
Number of blue pens = 5 u
Number of black pens = 1 u
Green pens + 5 u = 67 --- (1)
Green pens + 1 u = 31 --- (2)
(1) - (2)
5 u - 1 u = 67 - 31
4 u = 36
1 u = 36 ÷ 4 = 9
Number of black pens
= 1 u
= 9
(b)
Number of green pens in Box D
= 31 - 9
= 22
Number of green pens in both boxes
= 2 x 22
= 44
Answer(s): (a) 9; (b) 44