Problema Solution

Javier invests money in two accounts. He invests twice as much in an account paying 12% as he does in an account paying 7%. If he earns $310.00 in interest in one year from both accounts combined, how much did he invest altogether?

Answer provided by our tutors

Let

x = the money invested in an account paying 7%

y = the money invested in an account paying 12%

He invests twice as much in an account paying 12% as he does in an account paying 7%:

y = 2x

After 1 year he earns $310.00 in interest.

Money earned from the 12% account + Money earned from the 6% account = $310

0.07x + 0.12y = 310

by solving the system of equations

y = 2x

0.07x + 0.12y = 310

........

click here to see the system of equations solved for x and y

........

x = $1,000

y = $2,000

x + y = 1,000 + 2,000 = $3,000

Javier invested $3,000 altogether.