Question

Please help me. No fake and false answers please.

How many sequences a1, a2, a3, a4, a5 satisfy a1 < a2 < a3 < a4 < a5 can be formed if each a1 must be chosen from the set {1,2,3,4,5,6,7,8,9} ?

Please answer ASAP. need help.

Answer 1

Answer:126

Step-by-step explantion:

1. Any 5 numbers chosen from the set (1,2,3...,9) determine exactly one sequences of aj as indicated.

2. So the answer is the same as the number of ways of choosing 5 numbers from the 9 numbers in (1,2,...,9).

3. The answer is (9/5)=9*8*8*6/4!=126

Hope it helps have a great day.

Answer 2

Answer:

h to wo boli ki jai ho in Mumbai on February and March and April and May