Sammy has $15 more than Billy .mary has twice as much as Sammy. James has$5 less than Mary. Together they have $130.how much does each person have?

1 answer

B = Bill's money

S = Sammy's money

M = Mary's money

J = James's money

Sammy has 15 $ more than Billy.

S = B + 15

Mary has twice as much as Sammy.

M = 2 S = 2 ( B + 15 ) = 2 B + 2 * 15 = 2 B + 30

James has 5 $ less than Mary.

J = M - 5 = 2 B + 30 - 5 = 2 B + 25

Together they have 130 $

B + S + M + J = 130

Enter values B, M, J and S in this expression.

B + B + 15 + 2 B + 30 + 2 B + 25 = 130

6 B + 70 = 130 Subtract 70 to both sides

6 B + 70 - 70 = 130 - 70

6 B = 60 Divide both sides by 6

B = 60 / 6 = 10 $

S = B + 15 = 10 + 25 = 25 $

M = 2 B + 30 = 2 * 10 + 30 = 20 + 30 = 50 $

J = 2 B + 25 = 2 * 10 + 25 = 20 + 25 = 45 $