Find the sum of first 8 multiples of 3

• Arithmetic Progression (C10)

Find the sum of first 8 multiples of 3.

Answer

S = 3 + 6 + 9 + 12  + ... + 24

= 3(1 + 2 + 3 + ... + 8)

= 3 × (8 × 9)/2

= 108