Question

A person A can paint a house in 30 days. A second person B can paint the same house in 36

days. Both A and B work together for 15 days. Then, A goes away. The number of days that

B takes to complete the painting is (in days)
​

Answer 1

Hey Buddy

Here’s the answer

——————————————

# we’ll be solving this question with L.C.M. method

=> Now taking L.C.M. of 30 and 30

=> L.C.M. = 180 unit

So

A complete = 180/30 = 6 unit/day

B complete = 180/36 = 5 unit/day

If A and B work together

They complete = 6 + 5 = 11 unit/day


A.T.Q.

They work together for 15 days , so work competed

=> 11 * 15

=> 165 unit

Now work left = 180 - 165 = 15 unit

Further , A goes away and now B have to complete 15 unit work . And it will be completed in

=> 15 / 5

=> 3 days


HOPE HELPED

PEACE :)

Answer 2

LCM method

LCM=180

A = 6unit / day

B = 5 unit /day

A+ B = 11/unit /day

if they work for 15 day , work completed

15×11

165 unit

work left

180 - 165

15 unit

B have to complete it

15/5

3 days