Answer:
Maria have $123,75 more total money than Robert at the end of their investments.
Step-by-step explanation:
To calculate the simple interest we should multiply the Initial invest, with the interest without percentage and the time in years.
As the time is in months we have to divide it by 12 so we have the mesure of time in years, then the interest for each of the investments will be:
Maria
Invest = $4,000 Interest = 3.5/100=0.035 Time = 57/12 = 4.75
Simple Interest = 4,000 x 0.035 x 4.75 = $665
Total money at the end of the invest = $4,000 + $665 = $4,665
Robert
Invest = $3,500 Interest = 8.5/100=0.085 Time = 42/12 = 3.5
Simple Interest = 3,500 x 0.085 x 3.5 = $1,041.25
Total money at the end of the invest = $3,500 + $1,041.25 = $4,541.25
Now we have to subtract the total money of Robert from the total money of Maria to know how much money did she got over Robert after their invests
$4,665 - $4,541.25 = $123.75
At the end of the invest, Maria got $123,75 more than Robert
