Question

Three persons EB and C work together on a job and finish it finish it in 18 days if E and be working together can finish the job in 45 days find how long C working alone would take to complete it

Answer 1

Answer: 30 days

Explanation:

Working together, E & B get 1/45 of the job done per day

Working alone, C gets 1/x of the job done per day

Working together, E, B, & C get 1/18 of the job done per day.

`EB:(1)/(45)\qquad C: (1)/(x)\qquad EBC:(1)/(18)\\\\\\\\EB+C=EBC\\\\ (1)/(45)\ +(1)/(x)=(1)/(18)\\\\\\(45\cdot 18\cdot x)\bigg((1)/(45)+(1)/(x)=(1)/(18)\bigg)\\\\\\.\qquad \qquad 18x+810=45x\\\\.\qquad \qquad \qquad 810=27x\\\\.\qquad\qquad \qquad \large\boxed{30=x}`