Question

Niko makes beaded necklaces in three different sizes. How many more beads does it take to make 2 large necklaces than 2 medium necklaces? Explain how you found your answer.

Answer 1

3 beads

Explanation:

The different number of beads she selects can be determined by the number of ways 2 large necklaces can be formed from the 3 differents sizes of beads necklaces. Hence, lets take the ways 2 large necklaces to be 'r' and 3 differents sizes of beads neacklaces to be 'n.

Therefore, the relationship of r and n is nCr = n!/(n - r)!r! = 3!/2!(3 - 2)!

3C2 = 3*2*1/2*1 = 3