After using
45 of her rice flour, Mrs Chau bought another 18 kg of rice flour. As a result, Mrs Chau now has
105 as much rice flour as what she had at first. How many kilograms of rice flour did Mrs Chau have at first?
| |
Rice Flour |
Total |
| Before |
5 u |
5 u |
| Change 1 |
- 1 u |
|
| After 1 |
1 u |
|
| Change 2 |
+ 18 |
|
| After 2 |
1 u + 18 |
10 u |
Fraction of rice flour left after using
45 of it
= 1 -
45 =
15 Amount of rice flour left after using some = 1 u
Amount of rice flour after buying 18 kg of rice flour = 1 u + 18
1 u + 18 = 10 u
10 u - 1 u = 18
9 u = 18
1 u = 18 ÷ 9 = 2
Amount of rice flour that Mrs Chau had at first
= 5 u
= 5 x 2
= 10 kg
Answer(s): 10 kg
