Algebra homework help

Question

Problem : ​A rowing team practices rowing 2 miles upstream and 2 miles downstream. The team can row downstream 25% faster than they can row upstream.

a. Write and simplify an expression for the total amount of time the team spent rowing.

b. If the team rows 20 miles per hour upstream, how much time do they spend rowing?

Answer 1

Jason:

Remember that velocity*time=distance or v*t=d

let's call v_u the upstream velocity. we know v_d, the downstream velocity is 25% faster than the upstream velocity. This means v_d=1.25*v_u

we also know d=2. Time to row upstream is t_u=d/v_u=2/v_u

Time to row downstream is t_d=d/v_d=d/(1.25*v_u)=2/(1.25*v_u)=1.6/v_u

Total time is t_u + t_d = 2/v_u + 1.6/v_u

if v_u=20, you can plug that value in to find the total time spent rowing