I need help figuring out how much is borrowed.

Question

Gonzalez Manufacturing borrowed $30000. Part of the money was borrowed at 10%, part at 12%, and part at 14%. The total amount borrowed at 10% and 12% was twice the amount borrowed at 14%. Find the amount borrowed at each rate if the annual interest was $3680.

Answer 1

Let x= the percents

 

2x+x=30000

3x=30000

X=10000

 

So we know 10000 was borrowed at 14%

10000(.14)= 1400

3660-1400=2260

 

 

Now use

 

(1) x+y=20000

(2) 10%x+12%y=2260

 

Multiply (2) by 100 and use 12 in both x and y since value unknown

 

1200+1200=2400*100=240000

 

 

 

Then mult. Theinterest by 100. 226000

 

Then subtract 240000-226000=14000

 

So 12%=14000

10%=6000