Question

A can complete 50% of a job in 9 days and B can complete 25% of the job in 9 days if they worked alone. If they work together, how much of the job (in %) they can complete in 9 days?​

Answer 1

Answer:

given:-A completes 1/2 of the work in 9days.

Therefore,it will take 9×2=18days for A to complete the whole work.

Also given:-B completes 1/4 of the work in 9 days.

Therefore,B will/can complete the whole work in 9×4=36 days…

One day’s work of A=1/18(reason: you see, he completes the whole work in 18 days…therefore,he does 1/18th fraction of work in 1 day…or you can even say 1/18×18days=1(whole or complete job/work))

Similarly,B’s one day work=1/36.

Now if they work together,then obviously we have to add there one day work…

Therefore,A and B’s one day work together:-

1/18+1/36=1/12

So, they do 1/12th of the work in 1 day.

And,we are asked to find how much work is done in 9 days.

So,work done by them in 9 days will be:-9×(1/12)=3/4th of the job.

Answer:-3/4th of the whole work will be done by them in 9 days.

Also,ADDITIONAL INFO. The amount of work that will be left undone will be :-1–(3/4)=1/4

Let days taken to complete this work be x.

Therefore,x×(1/12)=1/4

X=3 days.

Therefore, total time taken by them to finish whole work will be:-3+9=12days…or we could have simply done it with another shortcut method…

Since,we know there one day work,is 1/12 .Let total no. Of days taken to complete the job be y.

Therefore,y×1/12=1.

Therefore,y=12days.

Upvote if you understood it…and please comment if you are facing some difficulty in understanding….i am happy to help you

Thanks for reading!