Yesterday i was doing the question of arithmetic progressions of class 10th math of exercise 5.2. How i solve this question in easy way Find the number of terms in each of the following A.P. (i) 7, 13, 19, …, 205

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# Find the number of terms in each of the following A.P. (i) 7, 13, 19, …, 205 Q.5(1)

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Therefore

First term, a= 7Common difference, d=a_{2}−a_{1}= 13 − 7 = 6Let there are

nterms in this A.P.a= 205_{n}As we know, for an A.P.,

a=_{n}a+ (n− 1)dTherefore, 205 = 7 + (

n− 1) 6198 = (

n− 1) 633 = (

n− 1)n= 34Therefore, this given series has 34 terms in it.