Question

sum of the following AP 2,7,12,...to 10 terms

Answer 1

the terms are
2,7,12,17,22,27,32,3742,47
so answer would be
2+7+12+17+22+27+32+37+42+47=245

Answer 2

AP = 2,7,12,......

a = 2

d = 7 - 2 = 5

$\tt{\rightarrow S_{n}=\dfrac{n}{2}[2a+(n-1)d]}$

$\tt{\rightarrow S_{10}=\dfrac{10}{2}[4+9(5)]}$

= 5(4 + 45)

= 5(49)

= 245

★Therefore :-

First 10 terms of the AP is 245.