Question

A and B take 6 hours and 9 hours respectively to complete a work. A works for 1 hour and then B works for two hours.

(i) How much work is done in these 3 hours ?

(ii) How much work is still left?​

Answer 1

Answer:

A takes 6 hours to finish work

And B takes 9 hours to finish the same work

∴ A’s 1-hour work = \frac{1}{6}

And B’s 1 hour’s work = \frac{1}{9}

And B’s 2 hours work = \frac{1}{9}\times2=\frac{2}{9}

(i) Now A’s 1 hours work + B’s 2 hours work = \frac{1}{6}+\frac{2}{9}=\frac{3+4}{18}=\frac{7}{18}

(ii) Work left = 1-\frac{7}{18}=\frac{18-7}{18}=\frac{11}{18}