Gonzalez Manufacturing borrowed $33000. Part of the money was borrowed at 8 %, part at 10 %, and part at 12 %. The total amount borrowed at 8 % and 10 % was twice the amount borrowed at 12 %. Find the amount borrowed at each rate if the annual interest was $3360.

Answer

given,

borrowed money = $33000

Part of the money was borrowed at 8 % be x, part at 10 % be y, and part at 12 % be ($33000-x-y)

x + y = 2 ($33000-x-y)

3 x + 3 y = $ 66000

x + y = $ 22000 ... (1)

third part = $33000 - ($22000)

= $ 11000

now annual interest is

0.08 x + 0.1 y + 0.12 * 11000 = $ 3360

0.08 x + 0.1 y = 2040 ... (2)

0.1 x + 0.1 y = 2200 ... (3)

solving equation (3) and (2)

x = $ 8000

y = $ 14000

3 rd number = $ 11000