Question

The sum of the 4thand 8thterm of an AP is 28and the sum of the 6thand 10thterm is 48. Find the AP.Also find the sum of first 20 terms.

Answer 1

Answer:

20th term =

an = a + (n -1) × d

an = -11 + (20 - 1) × 5

an = -11 + 19 × 5

an = -11 + 95

an = 84