Evaluate s5 for 600 + 300 + 150 + … what's the answer?

a.) 1,162.5
b.) 581.25
c.) 37.5
d.) 18,600

The answer is 1,162.5 ⇒ answer A

Step-by-step explanation:

The series is 600 + 300 + 150 + ......

∵ 300 ÷ 600 = 0.5

∵ 150 ÷ 300 = 0.5

- Each number multiplied by 0.5 to get the next number, that means

  we have constant ratio in this series between each tow consecutive

  terms then the series is geometric

- The rule of the sum of the geometric series is:

  , where a is the first term in the series,

  r is the constant ratio between each two consecutive terms and n is

  the position of the term in the series

- We need to find

∵ a = 600 , r = 0.5 and n = 5

Substitute all of these values in the rule above to find

∴

The answer is 1,162.5

step-by-step explanation:

20% of 120 is 24. if you subtract 24 from 120 you get 96