After using
15 of her sugar, Mrs Song bought another 10 kg of sugar. As a result, Mrs Song now has
95 as much sugar as what she had at first. How many kilograms of sugar did Mrs Song have at first?
|
Sugar |
Total |
Before |
5 u |
5 u |
Change 1 |
- 1 u |
|
After 1 |
4 u |
|
Change 2 |
+ 10 |
|
After 2 |
4 u + 10 |
9 u |
Fraction of sugar left after using
15 of it
= 1 -
15 =
45 Amount of sugar left after using some = 4 u
Amount of sugar after buying 10 kg of sugar = 4 u + 10
4 u + 10 = 9 u
9 u - 4 u = 10
5 u = 10
1 u = 10 ÷ 5 = 2
Amount of sugar that Mrs Song had at first
= 5 u
= 5 x 2
= 10 kg
Answer(s): 10 kg