Question

How many automatic progression with 10 terms are there whose first term is in the set 1234 and whose common difference is in the set 3 4 5 6 7?

Answer 1

Answer:

20

Step-by-step explanation:

Arithmetic progression, AP, depends upon its first term 'A' and common difference between two consecutive terms 'D'.

Here is the formula

Tn= A*(n-i)*D

1. we can choose first term in 4 ways.
2. we can choose common difference in 5 ways

Total number of arithmetic progression with 10 terms whose first term is in the set {1,2,3,4} and whose common difference is in the set {3, 4, 5, 6, 7} is  

4*5 =20

           number of terms don't matter because it isn't in the formula.