Which term of the sequence 3, 8, 13, 18, ... is 78 ?

The given sequence is:

3 , 8, 13, 18 , … 

Step 1: Identify the type of sequence

This is an arithmetic sequence where the first term (𝑎) is 3, and the common difference ( 𝑑) is:


𝑑 = 8 − 3 = 5

Step 2: Use the general formula for the  nth term

 =a+(n−1)⋅d

Substituting the given values:

78=3+(n−1)⋅5

Step 3: Solve for 

78−3=(n−1)⋅5

75=(n−1)⋅5


n−1= 75/5

​       = 15

n−1=15

n=16

Answer:

The 16th term of the sequence is 78.