Question

How many terms of Arithmetic sequence 2, 6, 10, 14... add upto 242

Answer 1

Given:

Arithmetic sequence 2, 6, 10, 14...

To find:

Number of terms whose sum is 242

Solution:

The given Arithmetic sequence 2, 6, 10, 14...

where,

• first term (a) = 2
• Common difference (d) = 6-2 = 4
• Sₙ = 242

The formula to find the sum is given by:

• Sₙ = n(2a+(n-1)d)/2

Putting the given values in the formula;

• 242 = n(4+(n-1)4)/2
• 484 = n(4+4n-4)
• 484 = n.4n
• n² = 484/4
• n² = 121
• n = √121
• n = 11

Number of terms whose sum is 242 is 11