College

Select the correct answer.

Ed is 7 years older than Ted. Ed's age is also [tex]\frac{3}{2}[/tex] times Ted's age. How old are Ed and Ted?

A. Ted is 15 years old, and Ed is 22 years old.
B. Ted is 14 years old, and Ed is 21 years old.
C. Ted is 13 years old, and Ed is 20 years old.
D. Ted is 12 years old, and Ed is 19 years old.

Answer :

Sure! Let's solve the problem step-by-step.

Let's use [tex]\( t \)[/tex] to represent Ted's age and [tex]\( e \)[/tex] to represent Ed's age.

We have two pieces of information:
1. Ed is 7 years older than Ted.
2. Ed's age is [tex]\(\frac{3}{2}\)[/tex] times Ted's age.

We can write these statements as equations:
1. [tex]\( e = t + 7 \)[/tex] (Ed is 7 years older than Ted)
2. [tex]\( e = \frac{3}{2} t \)[/tex] (Ed's age is [tex]\(\frac{3}{2}\)[/tex] times Ted's age)

We will solve these equations step-by-step:

### Step 1: Express one equation in terms of [tex]\( t \)[/tex]
From the second equation:
[tex]\[ e = \frac{3}{2} t \][/tex]

### Step 2: Substitute [tex]\( e \)[/tex] in the first equation
Substitute [tex]\( e \)[/tex] in the first equation with [tex]\(\frac{3}{2} t \)[/tex]:
[tex]\[ \frac{3}{2} t = t + 7 \][/tex]

### Step 3: Solve for [tex]\( t \)[/tex]
Subtract [tex]\( t \)[/tex] from both sides to get all terms involving [tex]\( t \)[/tex] on one side:
[tex]\[ \frac{3}{2} t - t = 7 \][/tex]

Combine like terms:
[tex]\[ \left(\frac{3}{2} - 1\right) t = 7 \][/tex]
[tex]\[ \frac{1}{2} t = 7 \][/tex]

Multiply both sides by 2 to solve for [tex]\( t \)[/tex]:
[tex]\[ t = 7 \times 2 \][/tex]
[tex]\[ t = 14 \][/tex]

So, Ted is 14 years old.

### Step 4: Find Ed's age
Use the first equation [tex]\( e = t + 7 \)[/tex] to find [tex]\( e \)[/tex]:
[tex]\[ e = 14 + 7 \][/tex]
[tex]\[ e = 21 \][/tex]

So, Ed is 21 years old.

Thus, the correct answer is:
B. Ted is 14 years old, and Ed is 21 years old.