Answer:
45
Step-by-step explanation:
Since the values are relatively small substitute i = 1 to 5 into 3i and sum
(3 × 1) + (3 × 2) + (3 × 3) + (3 × 4) + (3 × 5)
= 3 + 6 + 9 + 12 + 15
= 45
