Wendy can wash a car twice as fast as Jason. When they work together, Wendy and Jason can wash a large van in 2 hours. How many hours would it take Wendy to wash the van by herself?

Question

mathmale · Answer

I like to approach this sort of problem by writing out rates (in this case, rates of doing work, or, more specifically, time rates of doing a particular job.

Supposing we were to focus on Jason first.  What is his rate of completing this job / car wash?  Let$$J=Jason's~rate=\frac{ 1~job }{ 2~hours }$$

mathmale · Answer

Wendy (bless her) can wash the same car in half the time.  What is an expression for Wendy's rate:$$W=\frac{ 1~job }{ (\frac{ 1 }{ 2 })2~hours }=\frac{ 1~job }{ 1~hour }$$

anonymous · Answer

Oh alright. Thank you so much, let me get on to working this.

anonymous · Answer

rate of jason is j
rate of wendy 2j

work = rate * time
1 = (j + 2j) (2)

solve for j, the use it to find Wendey's rate. Use the rate of each persion to find the time

anonymous · Answer

I'm sorry I've got to go eat, but thank you so much xxferrocixx for the equation, I'll get right on it after! Appreciate it!