The total mass of 3 packets of black bean and 9 bags of rice was 36 kg. Each bag of rice was 4 kg lighter than each packet of black bean.
- What was the mass of 1 packet of black bean?
- What was the mass of 1 bag of rice?
(a)
Mass of a bag of rice = 1 u
Mass of a packet of black bean = 1 u + 4
3 x (1 u + 4) + 9 x 1 u = 36
3 u + 12 + 9 u = 36
3 u + 9 u = 36 - 12
12 u = 24
1 u = 24 ÷ 12 = 2
Mass of 1 packet of black bean
= 2 + 4
= 6 kg
(b)
Mass of 1 bag of rice = 1 u = 2 kg
Answer(s): (a) 6 kg; (b) 2 kg