Irene and Gem collected pens. Irene gave 30% of her pens to Gem. As a result, Gem's pens increased by 80%. If Irene had 224 pens left, find the total number of pens the two girls had at first.
| |
Irene |
Gem |
Comparing the change
in Gem's pens |
| Before |
10x4 =
40 u |
|
5x3 =
15 u |
| Change |
- 3x4 =
- 12 u |
+ 3x4 =
+ 12 u |
+ 4x3 =
+ 12 u |
| After |
7x4 =
28 u |
|
9x3 =
27 u |
30% =
30100 =
310 80% =
80100 =
45 The number of pens that Irene gave to Gem is repeated. Make the number of pens that Irene gave to Gem the same. LCM of 3 and 4 is 12.
Number of pens that Irene had in the end = 28 u
28 u = 224
1 u = 224 ÷ 28 = 8
Number of pens that Irene and Gem had at first
= 40 u + 15 u
= 55 u
= 55 x 8
= 440
Answer(s): 440
