1/5 of Chris's wire is equal to 1/4 of Sarah's. Daniel has 3 times as much wow as Sarah. In all, their wires measure 5 feet. How long is Chris's wire in feet.

2 answers

Chris' wire ---- x
Daniel's wire --- y
Sarah's wire ---- z

x + y + z = 5

1/5 x = 1/4 z
x = (5/4)z

y = 3z

sub into x+y+z = 5
(5/4)z + 3z + z = 5
times 4
5z + 16z = 20
21z = 20

z = 20/21
y = 20/7
x = (5/4)(20/21) = 25/21


check: 20/21 + 20/7 + 25/21 = 5 ✔
Daniel's is 3 times as much as Sarah's : y = 3z
20/7 = 3(20/21) ✔
1/5 of Chris's wire is equal to 1/4 of Sarah's.
(1/5)(25/21) = (1/4)(20/21)
5/21 = 5/21 ✔
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