Question

3. A blood bank needs twenty people to help with a blood drive. Twenty-five people have volunteered. How many different groups of twenty can be formed from the twenty-five volunteers?

Answer 1

Answer:

101 i think.

Step-by-step explanation:

My logic is:

make an initial group of 20, this will be G1. That is one group. Then, swap one of the remaining 5 for one of the 20. That makes 20 more groups for each person. 5*20=100, plus the first group, G1, makes 101 groups.

Answer 2

Answer:

5 a) Number of groups of 20 that can be formed

= 25C20

\small = \frac{25!}{5!*20!}

= 53130

b) Number of different meals possible = 2*7*3 = 42

Step-by-step explanation:

5 a) Number of groups of 20 that can be formed

= 25C20

\small = \frac{25!}{5!*20!}

= 53130

b) Number of different meals possible = 2*7*3 = 42