After using
15 of her chilli powder, Mrs Goh bought another 21 kg of chilli powder. As a result, Mrs Goh now has
115 as much chilli powder as what she had at first. How many kilograms of chilli powder did Mrs Goh have at first?
| |
Chilli Powder |
Total |
| Before |
5 u |
5 u |
| Change 1 |
- 1 u |
|
| After 1 |
4 u |
|
| Change 2 |
+ 21 |
|
| After 2 |
4 u + 21 |
11 u |
Fraction of chilli powder left after using
15 of it
= 1 -
15 =
45 Amount of chilli powder left after using some = 4 u
Amount of chilli powder after buying 21 kg of chilli powder = 4 u + 21
4 u + 21 = 11 u
11 u - 4 u = 21
7 u = 21
1 u = 21 ÷ 7 = 3
Amount of chilli powder that Mrs Goh had at first
= 5 u
= 5 x 3
= 15 kg
Answer(s): 15 kg
