Question

Which number best completes the pattern ?

17,12,7
3,7,11
21,16(?)

a. 12 b. 11 c. 8 d. 3​

Answer 1

b

Explanation:

The first series has a patten which is an=a(n-1)-5. The second series follow the pattern which is an=a(n-1)+4. The third series follow the pattern an=a(n-1)+5. So 16-5=11.

Answer 2

11

Explanation:

the common difference in the last sequence is 5 which can be gotten by subtracting the first term minus the second term.. therefore to find the next term you subtract 5 from the previous term,and 16-5 is 11.

I hope this helps