Age word problems 3

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Old school equations with Sal

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Age word problems 1
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Age word problems 3

Age word problems 3 Part 3 of the presentation on age word problems

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Age word problems 3

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Welcome to the third in this series of age word problems.
And I just wanted to start off where I left off
in the second one.
I got myself confused.
You guys make me very nervous while you just sit there
listening and I have to perform for you.
But, it turns out we did get the right answer, if you say
Arman is one hundred and fifty-three and Tarush is seven hundred and sixty-five, then eighty-five years ago Arman would
have been sixty-eight and Tarush would have been six hundred and eighty.
And notice that's ten times.
So it worked out.
So we're ready to tackle another problem.
One more problem.
Let's see.
This problem says, Zack is four times as old as Salman.
What a coincidence.
Salman really shows up in a lot of problems.
So Zack is four times as old as Salman.
Zack is also three years older then Salman.
How old is Zack?
Well, actually this one actually seems fairly
straightforward.
We're not dealing with the present and the future.
We're just dealing with the present.
So let's see if we can figure this out.
So we're trying to figure out how old is Zack.
Let's say, z for Zack.
z equals Zack.
It says Zack is four times as old as Salman.
So, Salman, if Zack is z, this first sentence,
let me circle it.
Zack is four times as old as Salman.
So, if Zack is four times as old as Salman, that means that Sal
is equal to Zack divided by four, But then it also says here that
Zack is also three years older than Salman.
Well, if Zack is also three years older than Salman, so
that means that also Sal would be Zack minus three.
The first sentence says Zack is four times as old as Salman.
So that means if you take Zack's age and divide it
by four, you get Sal's age.
The second sentence says Zack is also three years
older than Salman.
So that means if you take Zack's age and you subtract
three from it, you get Sal's age again.
Well, we have our equation set up.
And, actually, instead of writing Zack, I should
have just written z.
But the equation is all set up for us.
We get z over four is equal to z minus three.
We can multiply both sides of this equation times four and we'll
get z is equal to fourz, remember to distribute, minus twelve.
And then, we'll skip a couple of steps.
And I get threez is equal to twelve.
And I get Zack is equal to four years old.
Let's see if that makes sense.
If Zack is four years old, then this first sentence says Zack
is four times as old as Salman.
So that means Sal is one year old.
It also says Zack is three years older than Salman.
Well, that's consistent.
four is three more than one.
So we were right.
Zack is exactly four years old.
Hope that helps.
Have fun.
I think you're ready.
You've now seen, at least, every type of
the age word problems.
If you're still a little confused, you might just want
to re-watch the videos and maybe pause it right after I
give you the problem, and see if you can solve it yourself.
And remember, you had a lot of practice problems that you
can do on the actual modules themselves.
Have fun.

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At 5:31, how is the moon large enough to block the sun? Isn't the sun way larger?

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When naming a variable, it is okay to use most letters, but some are reserved, like 'e', which represents the value 2.7831...

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At 2:33, Sal says "double bonds" but should say "single bonds."

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