Question

In a certain lottery, 5 numbers between 1 and 13 inclusive are drawn. These are the winning numbers. How many different sections are possible? Assume that the order in which the numbers are drawn is not important.

a.1287
b.154,440
c.371,293
d.120

Answer 1

13 choose 5=13x12x11x10x9x8!/5x4x3x2x8!=1287
☺☺☺☺

Answer 2

Answer: 1287

Explanation:

When order of selecting things does not matter, then the combination od n things taking r at a time is given by :-

`^nC_r=(n!)/(r!(n-r)!)`

Given : The total numbers in lottery = 13

The total numbers to choose to win the lottery =- 5

Then , the combination of 13 numbers taken 5 at a time is given by :-

`^(13)C_r=(13!)/(5!(13-5)!)=1287`

Hence, the number of different selections = 1287