Question

Santiago has $6000 spread across his 3 accounts. He has a checking account which pays 2% interest, a savings account that pays 5% interest, and a money market account which pays 7% interest. At the end of 1 year, he earned a total of $355 in interest. If he put $2300 less in his savings accout than his money market account. Find how much money Santiago put into each account

Answer 1

Santiago put $700 into a checking account, $1,500 into a savings account and $3,800 into a money market account.

Explanation:

From the information given, you can write the following equations:

x+y+z=6000 (1)

0.02x+0.05y+0.07z=355 (2)

y=z-2300 (3)

First, you have to replace (3) in (1) and (2):

x+z-2300+z=6000

x+2z=8300 (4)

0.02x+0.05(z-2300)+0.07z=355

0.02x+0.05z-115+0.07z=355

0.02x+0.12z=470 (5)

Now, you have 2 equations:

x+2z=8300 (4)

0.02x+0.12z=470 (5)

Then, you can solve for x in (4):

x=8300-2z (6)

After this, you have to replace (6) in (5):

0.02(8300-2z)+0.12z=470

166-0.04z+0.12z=470

0.08z=304

z=3800

Now, you can replace z in (6) to find x:

x=8300-2(3800)

x=700

Finally, you can replace z in (3) to find y:

y=3800-2300

y=1500

According to this, the answer is that Santiago put $700 into a checking account, $1,500 into a savings account and $3,800 into a money market account.