Question

Last year today had 20000 to invest he invested some of it in an account that paid 6% simple interest per year and he invested the rest in to an account that paid 5% simple interest per year.After one year , he received a total of 1140 in interest.How much did he invest in each account

Answer 1

Answer:the amount of money that was invested in account A is $1400

the amount of money that was invested in account B is $6000

Explanation:

Let x represent the amount of money that was invested in account A

Let y represent the amount of money that was invested in account B.

Total amount of money invested in both accounts is $20000. It means that

x + y = 20000

The formula for simple interest is expressed as

I = PRT/100

Where

P = principal or amount invested

R =interest rate

T = time

For account A

P = x

T = 1 year

R = 6%

I = x × 6 × 1)/100 = 0.06x

For account B

P = y

T = 1 year

R = 5%

I = y × 5 × 1)/100 = 0.05y

After one year , he received a total of 1140 in interest. This means that

0.06x + 0.05y = 1140 - - - - - - - -1

Substituting x = 20000 - y into equation 1, it becomes

0.06(20000 - y) + 0.05y = 1140

1200 - 0.06y + 0.05y = 1140

- 0.06y + 0.05y = 1140 - 1200

- 0.01y - 60

y = - 60/ - 0.01 = 6000

Substituting y = 6000 into

x = 20000 - y, it becomes

x = 20000 - 6000 = 14000