Question

The first term of an AP is 10. The last term is 50. If the sum of all the terms is 480. Find the common difference and the number of terms

Answer 1

I know it will help you

Plzzzz marks me as brilliant

Answer 2

First term, a1 = 10

Last term, an = 50

Sum of all the terms = 480

Find the number of terms:

Sn = n/2 (a1 + an)

480 = n/2 (10 + 50)

480 = n/2(60)

480 = 30n

n = 480 ÷ 30

n = 16

Find the common difference:

an = a1 + (n - 1)d

50 = 10 + (16 - 1)d

50 = 10 + 15d

15d = 40

d = 8/3

Answer: There are 16 terms and the common difference is 8/3