Q10 of 47 Page 1

For what value of n, are the nth terms of two A.Ps 63, 65, 67,… and 3, 10, 17,… equal ?

As we know, nth term in A.P. is a + (n-1)d

Where, a is first term


n is Nth term


d is difference between terms


Given in one sequence, a1=63 and d1=2


In the other sequence, a2=3 and d2=7


Given nth term of both A.Ps are equal


So, a1+(n-1)d1=a2 +(n-1)d2


⇒63+(n-1)2=3+(n-1)7


⇒61+2n=-4+7n


⇒65=5n


⇒n=13


Conclusion: Therefore, for n = 13 it is equal.


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