A can do a piece of work in 12 days and B in 15 days. They work together for 5 days and then B left. The days taken by A to finish the remaining work is

Options

A. 10
B. 12
C. 3
D. 5

Answer

C

Explanation

`A_(e)=(1)/(12)`
`B_(e)=(1)/(15)`
A तथा B द्वारा 5 दिन में किया गया कार्य
`=5((1)/(12)+(1)/(15))=5((5+4)/(60))=(9)/(12)=(3)/(4)`
शेष कार्य `=1-(3)/(4)=(1)/(4)`
`:. A` द्वारा पूरा करने में लिया गया समय `=(1)/(4)xx12=3` दिन