Question

4,9,14........109
ANS:- 109=4 +(n-1) ×5
109-4=105=(n-1)×5
105=(5-1) where does this five comes from in brackets ????

Answer 1

It will be solved like this dear. ..

n+(n - 1)d = 109

4+(n - 1)5 = 109

4+ 5n - 5 = 109

5n - 1 = 109

5n= 110

n= 22

Got it??

U should have multiplied five with both n and 1.. ok