Question

Find the sum of 15 terms of an ap 2,7,12

Answer 1

AP: 2, 7, 12 . . .

a = 2

d = 5

n = 15

sn = n/2 (2a + (n - 1)d)

=> s15 = 15/2(4 + 14(5))

=> s15 = 15/2(74)

=> s15 = 15 × 37

=> s15 = 377

Answer 2

Step-by-step explanation:

the A.P is 2,7,12.......

sum of terms in A.P is =n/2( 2a + (n-1)d)

where a is first term and d is common difference

so sum = 15/2 [4+14(5)]

= 15/2(74)=15×37

hope this will help u