Answer:
9Kg, 18Kg and 63 Kg
Step-by-step explanation:
Sum the parts of the ratio, 1 + 2 + 7 = 10 parts
Divide the weight of sand by 10 to find the value of one part of the ratio
90 Kg ÷ 10 = 9 Kg ← value of 1 part of the ratio, thus
2 parts = 2 × 9 Kg = 18 Kg
7 parts = 7 × 9 Kg = 63 Kg
Thus the weights of each bag are 9 Kg, 18 Kg and 63 Kg