00:01
A sum of $10 ,000 is invested in three accounts.
00:05
So we have x plus y plus z equals 10 ,000.
00:15
They pay 6%, 8 % and 10 % interest.
00:19
Twice as much money is invested in the account paying 10 % as in the account paying 6%.
00:24
And the total annual interest for all three accounts is $842.
00:30
I'm going to write my percentages as decimals.
00:33
So that means that 0 .06x plus 0 .0 .0 .0 .5 .5 .5.
00:36
0 .08y plus 0 .1z equals that $842 that they earned an interest.
00:43
We're also told that twice as much money was invested in the account paying 10 % as the account paying 6%, which is x.
00:52
So that means 2x equals z.
00:55
Z is already isolated, so i'm going to go ahead and substitute that in.
00:59
Over here we get x plus y plus 2x equals 10 ,000.
01:03
And combine like terms, i get 3x plus y equals 10 ,000.
01:09
I'm going to solve for y, and i get 10 ,000 minus 3x.
01:14
I'm going to go ahead and substitute some things in over here...