Four friends are playing a "Guess my Age" game. The come up with the following clues. Dave's age is 15% of Sabrina. Luca's age is 75% of Sabrina and Rhianna is 300%
of Dave. The sum of their ages is 141. How old is Rhianna?
Show your work!

27 years old

Step-by-step explanation:

What I know

Let D = Dave, S = Sabrina, etc. Then:

(1)

(2)

(3)

(4)

Want to find R. Taking equation 3 and rewriting equation 4, we get

So if , then

by adding to both sides.

Using equation 1 and equation 2, I can rewrite everything in terms of and get:

by adding to both sides.

by dividing 2.35 both sides.

Now that I know Sabrina's age, I'll work towards getting Rhianna's using equation 1 and equation 3:

Checking my work:

Dave: 9

Sabrina: 60

Luca: 45 (since 9+60+45+27=141)

Rhianna: 27

9 is 15% of 60

45 is 75% of 60

27 is 300% of 9

step-by-step explanation: