Jason is 10 years older than Alex. Mark is 11 years younger than Alex. If the total of their ages is 68, how old is the youngest of them?

Mark is 12 years old.

Step-by-step explanation:

Let's just define some variables:

J = Jason

A = Alex

M = Mark

Next, let's put the information given in the question into equations.

Since Jason is 10 years older than Alex we can represent it like this:

J = A + 10

Since Mark is 11 years younger than Alex we can represent it like this:

M = A - 11

All of their ages add up to 68 so we can represent that like this:

J + A + M = 68

We can now do some substitutions to the J and M in this equation, like this:

(A + 10) + A + (A - 11) = 68

Combine like terms:

3A - 1 = 68

Solve for A

3A = 69

A = 23

Now that we found that Alex is 23 we can plug that back in to the first equations to find their ages:

J = 23 + 10

J = 33

M = 23 - 11

M = 12

Mark is the youngest out of the siblings being 12 years old.

Check:

23 + 33 + 12 = 68

68 = 68 :)

I hope this helps!!

- Kay :)

2. angles qrt and qst both measures 156 degrees.

step-by-step explanation:  

we have been given a diagram of a circle and we are told that measure of arc qvt is 156 degrees.  

we can see from our given diagram that angle qrt and angle qst subtends to arc qvt.

since we know that angles subtended by the same arc at the circumference are always equal.

by angle subtended by same arc theorem, measure of angle qrt and angle qst will be equal to the measure of arc qvt.

therefore, angles qrt and qst both measures 156 degrees and 2nd statement is the correct choice.