Problema Solution
The toll bridge is $3.00. A three month pass costs $7.50 and reduces the toll to $.50. How many crossings per three month period does it take for the three month pass to be the best deal?
Answer provided by our tutors
Let x = number of crossings in a 3-month period.
Plan A: each crossing costs $3.
Total cost: 3x dollars.
Plan B: flat rate of $7.50 plus $0.50 per crossing.
Total cost: 7.50 + 0.50x dollars
We want Plan B to be the best deal.
That is, the cost of Plan B will be less than Plan A.
Plan B < Plan A
7.50 + 0.50*x < 3*x
-2.50*x < -7.50
x > 3
It takes more than 3 crossings for the three month pass to be the best deal.