Abi and Kathy collected pens. Kathy gave 75% of her pens to Abi. As a result, Abi's pens increased by 10%. If Abi had 330 pens left, find the total number of pens the two girls had at first.
| |
Comparing the change
in Kathy's pens |
Kathy |
Abi |
| Before |
4x1 =
4 u |
|
10x3 =
30 u |
| Change |
- 3x1 =
- 3 u |
- 1x3 =
- 3 u |
+ 1x3 =
+ 3 u |
| After |
1x1 =
1 u |
|
11x3 =
33 u |
75% =
75100 =
34 10% =
10100 =
110 The number of pens that Abi gave to Kathy is repeated. Make the number of pens that Abi gave to Kathy the same. LCM of 1 and 3 is 3.
Number of pens that Abi had in the end = 33 u
33 u = 330
1 u = 330 ÷ 33 = 10
Number of pens that Kathy and Abi had at first
= 4 u + 30 u
= 34 u
= 34 x 10
= 340
Answer(s): 340
