S = weight of Susan's muffin
T = weight of Tom's muffin
18 of Susan's muffins weigh the same as 15 of Tom's muffins means:
18 S = 15 T
3 ∙ 6 S = 3 ∙ 5 T
Divide both sides b 3
6 S = 5 T
Divide both sides by 5
6 S / 5 = T
T = 6 S / 5
T = 1.2 S
1 Tom's muffin weigh the same as 1.2 Susan's muffins.
7 Tom's muffins weigh:
7 T = 7 ∙ 1.2 S
7 T = 8.4 S
8.4 S = 7 T
8.4 Susan's muffins weigh the same as 7 of Tom's muffins.
18 of Susan's muffins weigh the same as 15 of Tom's muffins. How many of Susan's muffins weigh the same as 7 of Tom's muffins?
1 answer