Question

Which expression describes the rule of this sequence?
3,6,9,12,15,18,…..?
A 3+ (n-1)
B 3n
C 3+ (3xn)
D 3+n

Answer 1

do you know that you label each number with its position, starting with 1
1 2 3 4...
3 6 9 12...

we call the label "n" so 3 has label 1 and 6 has label 2
if you use rule A : 3+(n-1) and try it for n=2, you should get 6 if it is the correct rule
3+ (2-1)= 3+1= 4. But 4 is not 6. so A is not the right answer.

Can you try the other rules and find the correct one?