Hint: Multiple of a number is that number multiplied by an integer. For finding the first five multiples, multiply that number with first fiver integers and add all of them.
Complete step-by-step answer:
First five multiple of 6 are; $6 \times 1, 6 \times 2, 6 \times 3, 6 \times 4, 6 \times 5$ = 6, 12, 18, 24, 30 Sum of first five multiple of 6 are = 6+12+18+24+30 = 90 Hence, the sum of the first five multiples of 6 is 90.
Note: Whenever we encounter these kinds of questions, we can see that numbers are making a sequence with having some common difference for e.g. Here it is 6. So instead of finding all multiples then adding we can also use formulas of arithmetic progression to solve this question.