Cora invests $1000 at 5% compounded semi-annually. How long will it take, to the nearest whole year, for her money to double? Use the formula A=P(1+r/n)^(nt),
where 0.05 and n=2 to find the answer.
It will take years for Cora's money to double when invested at 5%
compounded semi-annually
The solution is

15 Years or 14.5 Years

Step-by-step explanation:

According to the Question,

Put the Given value in Formula, We get

2000 = 1000 (1 + 0.05/2) ^ 2t

2 = (1+0.025)^2t

2 = (1.025)^2t   ⇔ 1.025^30 = 2.0975 ≈ 2

Thus, 2t = 30 ⇒ t = 15 Years

OR

2 = (1.025)^2t   ⇔ 1.025^29 = 2.0464 ≈ 2

Thus, 2t = 29 ⇒ t = 14.5 Years

if gloria has "carry over" minutes, (that is, any minutes paid for but not used in a month can be applied to her payment for minutes in the next month,) her total usage for the three months is: total minutes = 320 + 243 + 489 = 1052 minutes number of 200 minute blocks = 1052/200 = 5 r52 (that is 5 with a remainder of 52) rounding up the number of 200 minute blocks gives her usage for the three months as 6 blocks. the cost for six blocks is 6 x $25 = $150 she also has 200 - 52 or 148 carry over minutes if gloria pays each month and unused minutes are lost, applying the rounding up procedure to each month gives: first month usage of 320 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 second month usage of 243 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 third month usage of 489 minutes rounds up to 3 blocks of 200 minutes for a payment of 3 x $25 = $75 total payments for the three months are $50 + $50 + $75 = $175 get the plan with carry over minutes!