Question

Let ab be the diameter of circle with centre a point is taken outside fr the circle suck that pa and pb are the secants cuts the circle at

Answer 1

Let us consider that ,

The worker can complete the work in x hours .

So, he can complete 1/x part of work in 1 hour.

Now, The workers does 2/3 of what he does. So they do 2/3(1/x) part of work in 1 hour . 2/3x work in 1 hour .

Consider them all working together,

So work done in one hour, = 1/x + 2/3x + 2/3x = 3 + 4 / 3x = 7/3x .

So, They taken 1 hour to complete 7/3th part of work. So, In 3x/7 hours , They all can complete the work.

Ratio of the time taken by all instead of only one = 3x/7 : x = 3/7 .

So ,The required option is ( 1 )

Hope my answer helped you!