## IsabellaRose23 Group Title Show an equation and a solution for the problem. At the coal mine, it takes the older conveyor belt 20 hours to move one day's coal output. The new belt can do it in 15 hours. If the old belt began to move the day's output and the new belt started as well an hour later, how long would it take to move it? Round to the nearest tenth. 2 years ago 2 years ago

1. sheg Group Title

9.143 hrs

2. sheg Group Title

Old belt can complete 1/20 th of work in one hour and new belt can complete 1/15 th of the work in 1 hour thus both can complete $\frac{1}{20}+\frac{1}{15} = (\frac{7}{60})$ in one hour and as old belt started one hour before so work left = $1- \frac{1}{20} = \frac{19}{20}$ there fore together the two belts can complete the remaining work in $\frac{19}{20}\times \frac{60}{7} = \frac{57}{7} hrs$ therefore total time to complete the work = $1 + \frac{57}{7} = \frac{64}{7} = 9.142 hrs$

3. saifoo.khan Group Title

sheg is helping people these days!

4. sheg Group Title

b4 i dint used to help

5. saifoo.khan Group Title

Right.

6. sheg Group Title

fir mein kya karta tha mere bhai????

7. saifoo.khan Group Title

Tafreeiyan! ;)

8. sheg Group Title

haahahhaa.........achha hai boss

9. sheg Group Title

by d way mujhe iska matlab nahi pata hai!!!

10. saifoo.khan Group Title

LOL. great.