Question

for what value of n are the nth term of two AP : 63,65,67..... and 3,10,17...... are equal.
solve correctly ^_^

Answer 1

friend you should use the formula..
a nth term= a+(n-1)d

Answer 2

Given,
a = 63 , d = 2

tn = a + ( n -1 ) d
hence,
tn = 61 +2 n.........................(1)


&

tn = a + ( n - 1) d

tn = 3 + ( n -1 ) 7

therefore,
tn = 7n - 4..................................(2)


equating equation (1) nd (2)
61 + 2n = 7n -4

61+ 4 = 7n -2n

65 = 5n

hence,
n = 13.

hope it might be helpful !!