Jenny buys an 18'sandwich. Demi gets 1/2 the amount the Jenny gets. Joel gets 3/4 the amount Jenny gets. How much does Jenny get? Please explain.

Answer 1

I assume you meant 18 inches ( ' usually is the symbol for feet if I recall the imperial measure system)

jenny --> x inches
Demi--> half of that or x/2 inches
Joel --> gets 3/4 of Jenny's or 3x/4

x + x/2 + 3x/4 = 18
times 4

4x + 2x + 3x = 72
9x = 72
x = 8

Jenny gets 8 inches.

check:
Jenny -- 8
Demi --- 4
Joel ---- 6
total = 8+4+6 =18