Question

if it takes 2 programmers 2 days to write 2 programs, how many programmers are needed to write 20 programs in 20 days?

Answer 1

If 2 programmers write 2 programs in 2 days, then 1 programmer would write 1 program in 2 days. If it takes each programmer 2 days to write a program, and you have 20 days, then each programmer will be able to write 10 programs in that time period. So, you'll need 2 programmers to write 20 programs in 20 days.

Answer 2

One programmer will take 4 days to write 2 programs.
And one programmer will take 40 days to write 20 programs.
And two programmers will take 20 days to write 20 programs