Ineed ! what is the sum of the first 140 positive multiples of 3?
a) 10,010
b) 29,820
c) 29,610
d) 29,470

C

Step-by-step explanation:

The multiples of 3 are

3, 6, 9, 12, 15, ...........

The terms form an arithmetic sequence with common difference of 3.

The sum to n terms is

= [2a₁ + (n - 1)d ]

where a₁ is the first term and d the common difference

Here a₁ = 3 and d = 3, thus

= [ (2 × 3) + (139 × 3) ]

                            = 70(6 + 417) ] = 70 × 423 = 29610 → C

answer: the first one

step-by-step explanation: use a calculator and divide the minutes by the dollars.