Final answer:
Rob will earn $157.50 in 6 weeks.
Step-by-step explanation:
To calculate the amount of money Rob will earn in 6 weeks, we need to first calculate the number of hours he will babysit in that time. Since he babysits for 1.5 hours after school every day, he babysits for a total of 1.5 * 5 = 7.5 hours each week. In 6 weeks, he will babysit for 7.5 * 6 = 45 hours.
Next, we can calculate the total amount of money he will earn by multiplying the number of hours he babysits by his hourly rate. Rob earns $3.50 per hour, so his total earnings will be 45 * $3.50 = $157.50.