Question

the first term of ap is 5 and the last term is 45 and the sum os 400 find the number of terms and the common difference​

Answer 1

Answer:

Step-by-step explanation:

We know that Sₙ = n/2(a + l)

a= 5, l = 45, Sₙ = 400

400 = n/2(5 + 45)

=> n = 400 * 2 / 50 = 16.

nth term of AP is given by Tₙ = a + (n - 1)d

T₁₆ = 5 + 15d = 45

   => 15d = 40

   => d = 40/15 = 8/3.

Thus Number of terms = 16

        Common Difference = 8/3

Answer 2

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Number of terms = 16

Common difference = 8/3