Answer:
7
Step-by-step explanation:
625 - 576 = 49
square root of 49 = 7
F = 1/2 J = 2M
J = 4M
M + F + J = $280
M + 2M + 4M = $280
7M = $280
M = $280/7 = $40
J = 4M = 4x40 = $160
F = 1/2 (160) = $80
40 + 160 + 80 = $280
Mary saved $40
Fred saved $80
John saved $160
Robert is incorrect: Surface are of A is 30 + 30 + 42 + 42 + 35 + 35 = 214 square centimeters. Surface area of B is 120 + 120 + 168 + 168 + 140 + 140 = 856 square centimeters. B's surface area is 4 times as great as A's.
2nd option is the correct answer
sofia is correct.
