There are 11
people in an office with 3
different phone lines. If all the lines begin to ring at once, how many groups of 3
people can answer these lines?
Since there are 11 people in the office, the number of groups of 3 people that can answer the phone lines can be calculated using combinations.
The formula for combinations is nCr = n! / r!(n-r)!, where n is the total number of people and r is the number of people in each group.
In this case, n = 11 and r = 3.
Therefore, the number of groups of 3 people that can answer the phone lines is:
11C3 = 11! / 3!(11-3)!
11C3 = 11! / 3!8!
11C3 = 11 x 10 x 9 / 3 x 2 x 1
11C3 = 165
Therefore, there are 165 groups of 3 people that can answer the 3 phone lines in the office.