Mary and lewis each open a savings account at the same time. mary invests $3,700 in an account yielding 3.2% simple interest, and lewis invests $3,000 in an account yielding 5.9% simple interest. after fifteen years, who has the greater total amount of money, and how much greater is it?

Lewis has greater total amount of money by 179 dollar.

Step-by-step explanation:

The formula for Simple Interest is:   , where Amount of interest earned, Principal amount, Rate of interest in decimal form and time duration

Mary invests $3,700 in an account yielding 3.2% simple interest for 15 years.

So, the amount of interest will be:   dollar.

Thus, the total amount of money for Mary will be:  

Now, Lewis invests $3,000 in an account yielding 5.9% simple interest for 15 years.

So, the amount of interest will be:   dollar.

Thus, the total amount of money for Lewis will be:  

Now,  (5655 - 5476) dollar = 179 dollar.

So, Lewis has greater total amount of money by 179 dollar.

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.