The first volume of mathematics in the sixth grade of primary school (2) (1) Page 6 1 Practice, sort out and review the answers to all questions.

1. The cube volume ratio is the cube of the side length ratio: 2× 2× 2: 3× 3× 3 = 8: 27.

2. If number A is 20% more than number B, number A is (1+20%) times that of number B, that is, number A: number B =1+20% =120:100 = 6: 5.

3. Because the ratio of three sides is 3: 4: 5,

Therefore, let three sides be 3a, 4a and 5a.

Then 3a+4a=2.8

So a=0.4, so the two right angles are 1.2m and1.6m. ..

So the triangle area s =1/2×1.2×1.6 = 0.96 (square meter).

4. Assuming that the original bag of rice is x kg, the weight of the bag of rice is (80-x) kg.

Then (x-5): [(80-x)-7] = 8/9.

(x-5)×9=[(80-x)-7]×8

x=37