After using
35 of her sugar, Mrs Zhang bought another 20 kg of sugar. As a result, Mrs Zhang now has
75 as much sugar as what she had at first. How many kilograms of sugar did Mrs Zhang have at first?
| |
Sugar |
Total |
| Before |
5 u |
5 u |
| Change 1 |
- 1 u |
|
| After 1 |
2 u |
|
| Change 2 |
+ 20 |
|
| After 2 |
2 u + 20 |
7 u |
Fraction of sugar left after using
35 of it
= 1 -
35 =
25 Amount of sugar left after using some = 2 u
Amount of sugar after buying 20 kg of sugar = 2 u + 20
2 u + 20 = 7 u
7 u - 2 u = 20
5 u = 20
1 u = 20 ÷ 5 = 4
Amount of sugar that Mrs Zhang had at first
= 5 u
= 5 x 4
= 20 kg
Answer(s): 20 kg
