Question 844987
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Hi,
 it takes the cold water faucet 3 times as long to fill the tub as it does the hot water faucet in {{{ highlight_green(x) }}} time.
Question states***
 {{{1/(3x) + 1/x = 1/(3min)}}}   |Multiplying thru by 3x so as all denominators = 1
   1 + 3 = x
    4min = x, the time it takes for the hot water to fill the tub
Cold water fills the tub in 12min

CHECKING our answer***
{{{1/12 + 1/4 = 1/12 + 3/12 = 4/12 = 1/3}}}
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