Question

Gautam takes 5 hour to paint a wall and Gambhir takes 6 hours to paint the same wall . If they work together , how long will they take to paint to wall ?

Answer 1

Gautam takes 5 hours to paint the wall.

In 1 hour, Gautam will paint ( 1 / 5 ) of the wall.

Gambhir takes 6 hours to paint the wall.

In 1 hour, Gambhir will paint ( 1 / 6 ) of the wall.

Adding the part of wall Gautam and Gambhir paint in 1 hour,

( 1/5 + 1/6 )
( 6/30 + 5/30 )
( 11 / 30 )

Hence in 1 hour, Gautam and Gambhir will together paint ( 11 / 30 ) of the wall.

Therefore,

Gautam and Gambhir will together take ( 30 / 11 ) hours i.e. ( $\bold{2 \frac{8}{11} }$ ) hours to paint the wall.