Question

Find number of term in the AP A. 25 , 30 , 35 , 40 , ........120 B.100 , 98 , ......... 6 , 4

Answer 1

Answer:

Step-by-step explanation:

→A)$t_{n}=a+(n-1)d=120\\t_{n} =25+(n-1)5=120\\t_{n} =25+5n-5=120\\t_{n} =5n-20=120\\t_{n} =5n=140\\t_{n} =n=28\\ n=28$