Question

there are 5 speakers A,B,C,D and E. the number of ways in which A will speak always before B is

Answer 1

Since here the order matters, we will use permutations.

P = n! / (n - r)!

Where n is the total number of objects and r the number of objects picked at a time.

In our case :

n = 5

r = 2

Doing the substitution we have :

P = 5! / (5 - 2)!

= 5!/3!

(5 × 4 × 3 × 2 × 1) / (3 × 2 × 1)

5 × 4 = 20

20 ways.

Answer 2

Step-by-step explanation:

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