Question

What is the sum of the geometric sequence 3, 15, 75, … if there are 8 terms?

39,062
58,593
195,312
292,968

Answer 1

292,968

Explanation:

Step 1: Use geometric sequence formula
`s_n=(a1r^n)/(1-r)`

`S_n` &
`n`= the sum of geometric sequence & terms in total (8)

`r`= common ratio (5)

`a_1`= first term in sequence (3)

`s_8=(3(5)^(^8^))/( 1-5 )\\s_8=((3)390625)/(-4)\\s_8= (1171875)/( -4 )\\s_8=292968`

Answer 2

If you would like to know the sum of the geometric sequence, you can calculate this using the following steps:

3, 15, 75, 75 * 5 = 375, 375 * 5 = 1875, 1875 * 5 = 9375, 9375 * 5 = 46875, 46875 * 5 = 234375

3 + 15 + 75 + 375 + 1875 + 9375 + 46875 + 234375 = 292,968

The correct result would be 292,968.