After using
27 of her sugar, Mrs Chua bought another 30 kg of sugar. As a result, Mrs Chua now has
107 as much sugar as what she had at first. How many kilograms of sugar did Mrs Chua have at first?
|
Sugar |
Total |
Before |
7 u |
7 u |
Change 1 |
- 1 u |
|
After 1 |
5 u |
|
Change 2 |
+ 30 |
|
After 2 |
5 u + 30 |
10 u |
Fraction of sugar left after using
27 of it
= 1 -
27 =
57 Amount of sugar left after using some = 5 u
Amount of sugar after buying 30 kg of sugar = 5 u + 30
5 u + 30 = 10 u
10 u - 5 u = 30
5 u = 30
1 u = 30 ÷ 5 = 6
Amount of sugar that Mrs Chua had at first
= 7 u
= 7 x 6
= 42 kg
Answer(s): 42 kg