Question

The first term of an A. P. Is 5,the last is 45 and sum is 400.find the number of term and the common difference

Answer 1

Step-by-step explanation:

sn = n/2 (a + l)

400 = n/2 (5 + 45)

400 = n/2 × 50

400 = 25n

n = 400/25

n = 16

therefore the number of terms are 16

hope you get your answer