Question

The nth term of a sequence is 2n-1
The nth term of a different sequence is 3n+1
Work out the three numbers that are in both sequences and between 20 and 40

Answer 1

Answer:

The three numbers in both sequences have different term number n but same value. We can equalize each nth term in the question to "a" which represents one of the three numbers. a=2n-1, then n=(a+1)/2. a=3n+1, then n=(a-1)/3.