Kyra had $20,000 to invest. she decided to put the money into three different acounts earning 3%, 5%, and 7%
simple interest respectively, and she earned a total of $920.00 in interest. she invested half as much money at 7%
as at 3%. how much did she invest in each acount?
a. write a system of equations that models this situation.
b. find the amount invested in each acount

$8000, $4000 and $8000.

Step-by-step explanation:

Let the amount invested in 3%, 5% and 7% simple interest are a, b and c.

Given that, she invested half as much money at 7% as at 3%.

so, c=a/2, ⇒ a=2c. (1)

Now, a+b+c =20000 (2), ⇒3c+b =20000 {From equation (1)} (3)

She earned as interest a total of $920.

Hence, 3a/100+5b/100+7c/100 =920

⇒ 3a+5b+7c =92000

⇒13c +5b =92000 {From equation (1)} (4)

Solving equations (4) and (3), we get 13a+5(20000-3c) =92000

2c = 8000

⇒ c= 4000. then a= 2c =8000

Again from equation (2), b=20000-4000-8000=8000

Therefore, the amount invested in the three accounts are $8000, $4000 and $8000. (Answer)

4 candies

step-by-step explanation:

7 x 28 = 196

200 - 196 = 4 candies remaining.

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