Hello! In order to understand this question, we need to take a look at the content that is involved.
Lupita pays $40.03 in total. Meaning that's where we are going to start if we want to find out how many miles her ride was. Since the taxi charges a flat rate of $6.75. We would want to subtract it from her total value because we only work with that flat rate once. Which ends up giving us $33.28. From there, we don't need to worry about the flat rate anymore and we now focus on the mileage. If it costs $3.20 per mile, then we can simply divide the amount after to flat rate by the cost per mile, to figure out how many miles she has gone. In the end, you will get 10.4 miles.
You need to find the first common multiple of both 7 and 8. In this case, the LCM (lowest common multiple) is actually the numbers multiplies by each other, or 56. So the answer is 56 seconds