Question

= 53 - 60 = -7
4. Which term of the AP:
3, 8, 13, 18, . . . , is 78 ?
l. Given​

Answer 1

Answer:

78 is the 16th term

let's check

given difference between terms is 5

and first term is 3

so after 3 we will left 15 term

15×5=75

now add first term 3 in 75

75+3=78

Explanation:

common difference d= 8-3=5 (d=An-An-1)

and

An= A1+(n-1)×d

where An is nth term here given nth term is 78

we have to find n numbers of total term

78=3+(n-1)×5

(78-3)/5=n-1

75/5+1=n=16