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Among three people P,Q and R,P is the yungest and R is the oldest.The difference between the ages of P and Q is 6 years and R is 6 years elder to Q.If the average age of P and Q is 24 years , hat is the age of P.



Answer :

Answer:

P = 21

Step-by-step explanation:

Let's set up a system of equations to solve

We have 3 variables, P, Q are R

We know that Q and P have a age dfference of 6, and P is younger.

So:  P = Q - 6

And since R is 6 years elder to Q:  R = Q + 6

We also know that the avg age of P and Q = 24 so...

(P+Q)/2 = 24

Which can be written as P + Q = 48

Lets solve for P:

P = Q - 6 ; R = Q  + 6; P + Q = 48

Use the third equation to solve for Q:

P = 48 -Q

Plug into the first equation : P = Q - 6

48 - Q = Q - 6

54 = 2Q ; Q = 27

Now plug in Q = 27 to the first equation:

P = Q - 6

P = 27 - 6

P = 21


We didn't use the second equation but its always nice to have

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