Question

Find the 20th number Of
4,8,12,

Answer 1

hmm first ask yourself this...is that arithmetic progression? or geometric?

Answer 2

Geometric

Answer 3

What kind of operation ?

Answer 4

Multiplication

Answer 5

hmm try this to check..

8/4 = 12/8 ?

Answer 6

Oh then addition

Answer 7

If it's addition, it's just +4 every time.

Answer 8

So 80.

Answer 9

right! so the equation for arithmetic progression is...

an = a1 + (n-1)d

can you tell me which of these are given..which you're looking for?

an = ?
a1 = ?
n = ?
d = ?

Answer 10

@Numbers Is it crystal clear to you?