Hello,

The ratio of efficiency is A : B : C is 4: 5 : 6

Let work done is unity.

So, the total work done is 4x+ 5x + 6x = 1

So, x = 1 / 15

Hence, the total fraction of work done by A = 4x = 4 / 15

Talking percentage wise, Work Done by A = 4 x 100 / 15 %

So, Work Done by A = 26.67%

Best Wishes.

Since they completed the job together there amount of job done will be in the ratio of their efficiency that is 4:5:6.

Now the fraction of job done by P is 4/4+5+6

That is 4/15

If something is not clear mention in the comments.