+0

# Help?

0
142
2

Jack invests \$500 at a certain annual interest rate, and he invests another \$1000 at an annual rate that is one-half percent higher. If he receives a total of \$65 interest in 1 year, at what rate is the \$500 invested?

Guest May 22, 2017
Sort:

#1
+1

Jack invests \$500 at a certain annual interest rate, and he invests another \$1000 at an annual rate that is one-half percent higher. If he receives a total of \$65 interest in 1 year, at what rate is the \$500 invested?L

Let the \$500 be invested @ x,

\$1,000 will be invested x + 0.5, but we have:

500*x/100  + 1,000*(x/100 + 0.005) = 65, solve for x

Solve for x:
1000 (x/100 + 0.005) + 5 x = 65

Put each term in x/100 + 0.005 over the common denominator 100: x/100 + 0.005 = x/100 + 0.5/100:
1000 x/100 + 0.5/100 + 5 x = 65

x/100 + 0.5/100 = (x + 0.5)/100:
1000 (x + 0.5)/100 + 5 x = 65

1000/100 = (100×10)/100 = 10:
10 (x + 0.5) + 5 x = 65

10 (x + 0.5) = 10 x + 5.:
10 x + 5. + 5 x = 65

Grouping like terms, 10 x + 5 x + 5. = (10 x + 5 x) + 5.:
(10 x + 5 x) + 5. = 65

10 x + 5 x = 15 x:
15 x + 5. = 65

Subtract 5. from both sides:
15 x + (5. - 5.) = 65 - 5.

5. - 5. = 0:
15 x = 65 - 5.

65 - 5. = 60.:
15 x = 60.

Divide both sides of 15 x = 60. by 15:
(15 x)/15 = 60./15

15/15 = 1:
x = 60./15

60./15 = 4.:

Guest May 22, 2017
#2
+91229
+1

Jack invests \$500 at a certain annual interest rate, and he invests another \$1000 at an annual rate that is one-half percent higher. If he receives a total of \$65 interest in 1 year, at what rate is the \$500 invested?

Here is a start  :)

I am using I=PRT which is the same for both simple and compound interest if the time unit is just one. i.e. t=1

Solve this and you will get the initial rate as a decimal. Multiply it by 100 to get  the percentage.

\(65 = 500*r+1000(r+0.005)\)

Melody  May 22, 2017

### 6 Online Users

We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details