Question

here are 1515 people in an office with 55 different phone lines. If all the lines begin to ring at once, how many groups of 55 people can answer these lines?

Answer 1

Answer:

360,360 groups of 5 people.

Step-by-step explanation:

We have been given that there are 15 people in an office with 5 different phone lines. We are asked to find groups of 5 people that can answer these lines, if all the lines begin to ring at once.

We will use fundamental principle of counting to solve our given problem.

There are 15 people to answer 1st line, that will leave us with 14 people to answer 2nd line.

Now, we will have 13 people to answer 3rd line, that will leave us with 12 people to answer 4th line.

There are 11 people to answer 5th call.

So 5 lines can be answered in $15\times 14\times 13\times 12\times 11=360,360$ ways.

Therefore, 360,360 groups of 5 people can answer these lines.