- #1

harpazo

- 208

- 16

- Homework Statement
- For each problem, find the current age.

- Relevant Equations
- A. x + 10 = 3x

B. K + 20 = 4K

Last two practice age word problems for today. More tomorrow for sure.

1. Ten years from now, Orlando will be three times older than he is today. What is his current age?

Let x = Orlando's current age.

Let x + 10 = Orlando's age 10 years from now.

x + 10 = 3x

10 = 3x - x

10 = 2x

10/2 = x

5 = x

Orlando is 5 years old.

Check:

x + 10 = 3x

5 + 10 = 3(5)

15 = 15

My x-value checks to be true. 2. In 20 years, Kayleen will be four times older than she is today. What is her current age?

Let K = Karen's current age.

Let K + 20 = Karen's age in 20 years.

K + 20 = 4K

K - 4K = -20

-3K = -20

K = -20/-3

K = 20/3

Karen is 20/3 years old.

Let 20/3 = 6.6666666667

Rounding to one decimal place, I get 6.7.

I say Karen is 6 years, 7 months old.

Should it be 6 years, 7 days?

Check:

K + 20 = 4K

Let K = 20/3

(20/3) + 20 = 4(20/3)

26.6 = 80/3

26.6 = 26.6

1. Ten years from now, Orlando will be three times older than he is today. What is his current age?

Let x = Orlando's current age.

Let x + 10 = Orlando's age 10 years from now.

x + 10 = 3x

10 = 3x - x

10 = 2x

10/2 = x

5 = x

Orlando is 5 years old.

Check:

x + 10 = 3x

5 + 10 = 3(5)

15 = 15

My x-value checks to be true. 2. In 20 years, Kayleen will be four times older than she is today. What is her current age?

Let K = Karen's current age.

Let K + 20 = Karen's age in 20 years.

K + 20 = 4K

K - 4K = -20

-3K = -20

K = -20/-3

K = 20/3

Karen is 20/3 years old.

Let 20/3 = 6.6666666667

Rounding to one decimal place, I get 6.7.

I say Karen is 6 years, 7 months old.

Should it be 6 years, 7 days?

Check:

K + 20 = 4K

Let K = 20/3

(20/3) + 20 = 4(20/3)

26.6 = 80/3

26.6 = 26.6