SAT Diagnostic #2
|Basic Algebra||Basic Equations|
And here are the potential answers…
As you know, a full day of school can really sap your energy. [Tired boy sleeping after a exhausting day at school]
So it’s no surprise that Lance is draggin’ a bit on the way home.
This question is asking about the difference that those 2 miles an hour make… [Road leading from school to lance's home]
…since they lost Lance an extra 15 minutes.
Time that could have been well spent doing math homework. [Boy doing math homework]
Okay, formula time.
There's a basic equality here – since Lance is traveling the same distance both ways. [Lance travelling down a road from home to his school and riding back]
It's just taking him a little longer on the way back home.
Pick up the pace, boy…
All right…so let’s call the 12 miles per hour average Lance took to get to school “12x”…
…and the time it took him to get home “10x + 0.25”.
The 10x represents his average speed on the way home…
… and the “0.25” represents the extra quarter of an hour it takes him to pedal his [clock ticking by]
Because Lance is traveling an equal distance both times, we can say that 12x = 10x + 2.5.
Take away 10x from both sides…
And we get 2x = 2.5.
Divide both sides by 2 and we have a value for our “x”…1.25 hours. [2x and 0.25 divided by 2]
That’s nice and all… but we’re solving for distance. [Boy shrugging his shoulders at math equations]
So we still have to multiply the time by Lance’s average speed.
We take 1.25 hours multiplied by 12 miles per hour which gives us our final answer…15
Looks like the answer is option E – Lance has a 15 mile ride to and from school. [Lance cycles across the screen]
We get tired driving our car for 15 miles… [Man falling asleep on his steering wheel]