Question

if second and the third terms of an a.p are 24 and 28 respectively then find the sum of first 61 terms​

Answer 1

Answer:

Please find the attachment of the arithmetic progression question below:

Answer 2

Step-by-step explanation:

Second term = 24

= (a+d)= 24........ (1)

third term = 28

= (a+2d) = 28 ......(2)

subtracting (1) from (2) , we get

(a+2d) - (a+d) = 28-24

= d = 4

putting d=4 in (1) , we get

a+4 = 24

a = 24 - 4

a= 20

Now,

Sum of first 6th term = n/2 (2a + (n-1)×d

= 61/2 (2×20 + (61-1)×4

= 61/2 (40 + 60 × 4)

= 61/2 (40 + 240 )

= 61/2 (280)

= 61 × 140

= 8540 is the answer..