mary and lewis each open a savings account at...
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? a. lewis has $879 more than mary. b. lewis has $179 more than mary. c. mary has $776 more than lewis. d. mary has $345 more than lewis.
Answer
# Explanation:
## Step1: Calculate Mary's simple - interest amount
The simple - interest formula is $I = Prt$, where $P$ is the principal amount, $r$ is the annual interest rate (in decimal form), and $t$ is the time in years. For Mary, $P = 3700$, $r=0.032$, and $t = 15$.
$I_{Mary}=3700\times0.032\times15$
$I_{Mary}=3700\times0.48 = 1776$
The total amount of money in Mary's account, $A_{Mary}=P + I_{Mary}=3700 + 1776=5476$.
## Step2: Calculate Lewis's simple - interest amount
For Lewis, $P = 3000$, $r = 0.059$, and $t = 15$.
$I_{Lewis}=3000\times0.059\times15$
$I_{Lewis}=3000\times0.885=2655$
The total amount of money in Lewis's account, $A_{Lewis}=P + I_{Lewis}=3000 + 2655 = 5655$.
## Step3: Find the difference between their amounts
$A_{Lewis}-A_{Mary}=5655 - 5476=179$
# Answer:
b. Lewis has $179 more than Mary.