Answer:
(a) 5kg
Explanation:
Given that the total weight of a bag of rice and a bag of yam flour is 20 kg, and that the rice weighs three times as much as the yam flour, we can set up the following equation:
Let x be the weight of the bag of yam flour.
Then the weight of the bag of rice is 3x.
The total weight is the sum of the weights of the two bags, which is 20 kg:
x + 3x = 20
4x = 20
x = 5
Therefore, the weight of the bag of yam flour is 5 kg. The answer is (a) 5kg.