Question

) Sum of first five multuiples of 3 is...
(A) 45 (B) 55
(C) 15
(D) 75​

Answer 1

Answer:

Option no c. 15 is your answer dear..

Answer 2

Answer:

(A) 45

Step-by-step explanation:

The first five multiples of 3 are 3, 6, 9, 12 and 15.

Given:

first term, a = 3

common difference, d = 6-3 = 3

number of terms, n = 5

Sn = n/2 {2a + (n-1)d

S5 = 5/2 [2a + (5-1)d]

= 5/2 [2 × 3 + 4 × 3]

= 5/2 (6 + 12)

=5 × 9

= 45