Question

For what value of n, are the nth terms of 2 APs 63,65,67,... and 3,10,17,... are equal?

Answer 1

in first AP
a=63,d=2
nth term=63+(n-1)2=63+2n-2=2n+61

in second AP
a=3,d=7
nth term=3+(n-1)7=3+7n-7=7n-4

7n-4=2n+61
5n=65
n=65/5=13
thus, n=13