Confused

[trist666]

I solved this word equation about term deposits.. and somehow got a negative answer for y. Maybe someone could help, tell me if I'm wrong.
The question is:

Zach invested in a term deposit that paid 4% interest per annum and in a bond that paid 6% per annum. If he invested a total of $13 000 and earned $700 interest in a year, how much did he invest at each rate? Solve using a system of two equations and two variables.

The equations that I got were x+y=13 000 and 0.4x+0.6y=700
with x equaling the amount invested at 4% and y equaling the amount invested at 6%.

The answers I got were x=35500 and y= -25500.
Is it possible for y to be a negative number?

 

[soroban]

Hello, trist666!

You made a simple error . . .

Zach invested in a term deposit that paid 4% interest per annum and in a bond that paid 6% per annum.
If he invested a total of $13 000 and earned $700 interest in a year, how much did he invest at each rate?
Solve using a system of two equations and two variables.

The equations that I got were: x + y = 13000 and 0.4x + 0.6y = 700 \(\displaystyle \;\) . . . here1

4% = 0.04 and 6% = 0.06 . . . but you knew that, right?

 

[trist666]

Wow.. I completely missed that, the most simple error. haha
Thanks.

 

[Denis]

Wow.. I completely missed that, the most simple error. haha
Thanks.

It's unfortunate that % is pronounced "per cent";
"per hundred" would save lots of confusion with rookie students;
that problem does not exist in French: cent = 100