contestada

Suppose that Mr. and Mrs. Riggs want to name their new daughter so that her initials (first, middle, and last) will be in alphabetical order with no repeated initial. How many such triples of initials can occur under these circumstances? Note: the last initial must be an R g

Respuesta :

JeanaShupp

Answer: 136

Step-by-step explanation:

Total letters in English alphabet= 26

Since , the last name starts with R , and R comes at 18th position in the English alphabet series.

So the choices left for the first and the middle name would be 26-18=17

The number of ways to select any 2 alphabet from 17 with no repeated initial would be:

[tex]^{17}C_{2}=\dfrac{17!}{2!15!}=\dfrac{17\times16}{2}=136[/tex]  [ ∵[tex]^nC_r=\dfrac{n!}{r!(n-r)!}[/tex]]

Hence, the number of such triples of initials can occur under these circumstances = 136

Otras preguntas