Answer:
15 ways
Step-by-step explanation:
We are given that a set S={E,F,G,H,J}
We have to find the number of ways to select two members from S with repetition.
Combination formula
[tex]\binom{n}{r}=\frac{n!}{r!(n-r)!}[/tex]
We have n=5 , r= 2
Number of ways in which two members from S can be selected when repetition is not allowed=[tex]5C_2=\frac{5!}{2!(5-2)!}[/tex]
Number of ways in which two members from S can be selected when repetition is not allowed=[tex]\frac{5\times4\times3!}{2\times1 3!][/tex]
Number of ways in which two members from S can be selected when repetition is not allowed=[tex]5\times 2=10[/tex]
When a member repeat then combination
{E,E},{F,F},{G,G},{H,H},{J,J}
There are 5 combination when a member is repeat and select two members from S.
Total number of ways in which to select two members from S with repetition =10+5=15 ways
