Charlie had 28 pens. ⁴₇ were green and the rest were yellow and pink. The ratio of the number of yellow pens to the number of pink pens was 1 : 5. Charlie decided to give away some green pens to decrease the number of green pens to half of the total number of pens.

1. How many more green pens than yellow pens did he have at first?
2. How many green pens did he have to give away?

Green pens	Yellow pens	Pink pens	Total
4x2	3x2
	1x1	5x1
8 u	1 u	5 u	28

	Green pens	Yellow pens	Pink pens
Before	8 u	1 u	5 u
Change	- ?
After	6 u	6 u
Comparing green, yellow and pink pens in the end	1	1

(a)
The total number of yellow pens and pink pens is repeated. Make the total number of yellow pens and pink pens the same.  LCM of 3 and 6 is 6.

Total number of pens at first
= 8 u + 1 u + 5 u
= 14 u

14 u = 28

1 u = 28 ÷ 14 = 2

Number of more green pens than yellow pens at first
= 8 u - 1 u
= 7 u
= 7 x 2
= 14

(b)
Number of more green pens that Charlie had to give away
= 8 u - 6 u
= 2 u
= 2 x 2
= 4

Answer(s): (a) 14; (b) 4