Question

Find the sum of an AP 3, 7, 11, 15. 99.​

Answer 1

Step-by-step explanation:

Step-by-step explanation:Let us assume that 79 is the nth term of the A.P.

Step-by-step explanation:Let us assume that 79 is the nth term of the A.P.Now, the A.P. is given by 3, 7, 11, 15,

Step-by-step explanation:Let us assume that 79 is the nth term of the A.P.Now, the A.P. is given by 3, 7, 11, 15,So, the series has the first term (a), 3 and the common difference (d), 4.

n = 20.

n = 20.So,the 20th term of the A.P. is 79.

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