Erin had $6,191.50 in a savings account with simple interest. She had opened the account with $6,100 just six months earlier. What was the interest rate?

  3%

Step-by-step explanation:

Erin earned 6191.50 -6100 = 91.50 in interest in 6 months on a 6100 principal. Then the annual interest rate is ...

  I = Prt

  r = I/(Pt) = 91.50/(6100·6/12) = .03 = 3%

The interest rate was 3%.

the interest rate is 3%

Step-by-step explanation:

The formula for determining simple interest is expressed as

I = PRT/100

Where

I represents interest paid on the amount invested.

P represents the principal or amount invested.

R represents interest rate

T represents the duration of the investment in years.

From the information given,

P = $6100

Interest = total amount earned - principal. Therefore,

I = 6191.50 - 6100 = $91.5

T = 6 months = 6/12 = 0.5 year

Therefore,

91.5 = (6100 × R × 0.5)/100

91.5 = 30.5R

R = 91.5/30.5

R = 3%

3

step-by-step explanation:

in standard form:

a= dictionaries

b= maps

you have to buy 3 dictionaries, so put a 3 next to the a (dictionaries) so that you can multiply them by each other.

a3+b= 60 (the amount of money you have)

we already know the cost of a=15 so replace a with $15

($15 x 3)+b=60

multiply 15 and 3 to get $45 and replace it with $45

45+b=60

and then replace b with 15 to get the total:

45+15=60

that means you have $15 left after buying 3 dictionaries.

15 divided by the cost of a map ($5) equals 3.

so you can buy 3 maps.

sorry if it was confusing!