Question

If the first term in an arithmetic series is
3, the last term is 136, and the sum is 1,390, what are the first 3 terms?

Answer 1

3, 10, 17

Answer 2

How did you find this out?

Answer 3

Using Arithmetic Sum equation
Sn=(n/2)(a_0+a_n)
1390=(n/2)(3+136)
n/2=10
n=20

Arithmetic Sequences
A_n= A_0 + d(n-1)
136= 3 + d(20-1)
133=19d
d=7