Question

In the arithmetic sequence, 1, 5, 9, 13..., which term equals 57
a. 13
b. 14
c. 15
d. 16​

Answer 1

Answer:

AP= 1,5,9,13

a= 1

d= 4

If 57 is a term of this AP then

An=57

An= a+(n-1)d

57= 1+(n-1)4

56= n-1(4)

56/4=n-1

14= n-1

15=n

So 57 is the 15th term of this AP