An investor has s400000 in three accounts paying 6 8 and 10...

An investor has $400,000 in three accounts, paying 6%, 8%, and 10%, respectively. If she has twice as much invested at 8% as she has at 6%, how much does she have invested in each account if she earns $36,800 in interest? At 6%, she has invested $ At 8%, she has invested $ At 10%, she has invested $

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Transcript

00:01 An investor has $400 ,000 in three accounts, paying $6 ,8, and 10%.

00:06 If she has twice as much invested at 8 % as she does 6%, how much does she have invested in each account if she earns $36 ,800 in interest? so the key amount here, the key phrase, is she has twice as much invested at 8 % as 6%.

00:25 She has more at 8%.

00:27 So if we know she has x amount at 6%, then she has twice that amount at 8%.

00:35 So how much at 10 %? well, if you take the $400 ,000 and you subtract what she invested at 6%, and you subtract what she invested at 8%, then you have the amount invested at 10%.

00:51 So how does that work with the interest? well, we know the interest is principle times rate times time.

00:59 Since we're looking at one year, then time is just one, so we're not worried about that.

01:04 So the interest is going to be the principle times the rate.

01:08 So let's look at this 6%.

01:10 That's going to be 0 .06, which is my rate, times my amount, which is x.

01:16 We look at this, that's going to be 0 .08 times 2x.

01:20 If we look at the last one, we're looking at 0 .10 times 400 ,000 minus 3x.

01:28 So that's the amount she made in interest in each account.

01:32 When you add those together, you're going to get the amount that she earned in interest, which is at $36 ,800.

01:40 So now we have an equation to solve...

Question

Please give Ace some feedback