Question 379034
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Hi,
D = r*t OR t = D/r   Question sets up an equality according to time it takes
Let c represent the rate of the current
{{{121km/(4kmph + c) = 6km/(4kmph - c)}}}
cross mulitply to solve for x
121(4 - c) = 6(4 + c)
484 - 121c = 24 + 6c
460 = 127c
3.622kmph = c, the rate(speed) of the current