Question

The first term of an AP is 5, the last term is 45 and the sum is 400. Find the

number of terms and the common different​

Answer 1

AnSwEr :

first term a = 5, last term l = 45 and s^n = 400

since,Sn = n/2(a + l)

= 400 = n/2(5+ 45)

= 400 = n/2(50)

= 400 = n(25)

= n = 16

since, l = a + (n–1)d

= 45 = 5+(16–1)d

= 45 – 5 = (15)d

= 40 = (15)d

= 40/15 = d

i,e., d = 40/15

= d = 8/3

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Akanksha✌✌❤

Answer 2

Answer:

Answer is given in attachment.