In planning her retirement, Liza deposits some money at 2.5% interest, with twice as much deposited at 4.5%. Find the amount deposited at each rate if the total annual interest income is $2070

Answer 1

2.5 +2(4.5) =2070

.025x +.09x =2070

.115x = 2070

x = 2070/.115= $18,000 = amount invested at 2.5%

twice as much invested at 4.5% is $36,000

check the answer

.025 times 18000=450

.09 times1800 =1620

1620+450= 2070

(trivial detail. That 18,000 number is depressing, if you noticed a recent news item: a Texas Dairy Farm fire killed 18,000 cows, )

Answer 2

Hi Marc L

$18000 at 2.5%

$36000 at 4.5%

Let = x amount deposited at 2.5%

Let 2x = amount deposited at 4.5%

Total interest earned = 2070

.025x + .045(2x) = 2070

.025x + .09x = 2070

0.115x = 2070

x = 18000

2x = 36000

Checking

.025(18000) + .045(36000) = 450 + 1620 = 2070

Hope this helps.