Wilde Oscar worked frantically for 4 hours and called for help because he saw it would take 6 more hours to finish. Calm Sally began to help and they finished the job in 2 more hours. How long would it have taken Sally to do the job alone?

Question

anonymous · Answer

working alone, oscar would take 10 hours, so in each hour he does1/10 of the job; in the six hours he worked, he did 6/10 of the job 

this means that sally did 4/10 of the job in 2 hours, for a rate of 1/5 of the job per hour, so she would take five hours for the whole job

anonymous · Answer

how did you get that answer?

anonymous · Answer

she basically just worked it out for you.

anonymous · Answer

so her answer is correct.