Question

Toni rows a boat 4.5 km/h upstream and then turns around and rows 5.5 km/h back downstream to her starting point. If her total rowing time is 48 min, for how long does she row upstream? Express your answer to the nearest minute.

Answer 1

distance upstream equals distance downstream.
Using tu for time upstream, and td for time downstream,
and using rate x time= distance, you have
4.5*tu= 5.5*td
also, the total time is tu+td= 48/60 (in hours! not minutes)
replace td with td= 48/60 - tu
4.5*tu= 5.5*(4/5 - tu)
where we simplified 48/60 to be 4/5 (divide top and bottom by 12)
now solve for tu