Question

Four years ago the average age of A,B and C was 25 years. Five years ago the average age of B and C was 20 years. A's present age is ​

Answer 1

Dear ,

the answer is : A = 37 years how the answer came is follow the given steps

Let the present ages of A,B,C be x,y and z years respectively.Given,

 3(x−4)+(y−4)+(z−4)=25

3(x−4)+(y−4)+(z−4)=25⇒x+y+z−12=75

3(x−4)+(y−4)+(z−4)=25⇒x+y+z−12=75⇒x+y+z=87   .....(1) and 

3(x−4)+(y−4)+(z−4)=25⇒x+y+z−12=75⇒x+y+z=87   .....(1) and 2(y−5)+(z−5)=20

3(x−4)+(y−4)+(z−4)=25⇒x+y+z−12=75⇒x+y+z=87   .....(1) and 2(y−5)+(z−5)=20⇒y+z−10=40

3(x−4)+(y−4)+(z−4)=25⇒x+y+z−12=75⇒x+y+z=87   .....(1) and 2(y−5)+(z−5)=20⇒y+z−10=40⇒y+z=50   ....(2)

3(x−4)+(y−4)+(z−4)=25⇒x+y+z−12=75⇒x+y+z=87   .....(1) and 2(y−5)+(z−5)=20⇒y+z−10=40⇒y+z=50   ....(2)From equations (1) and (2), we have

3(x−4)+(y−4)+(z−4)=25⇒x+y+z−12=75⇒x+y+z=87   .....(1) and 2(y−5)+(z−5)=20⇒y+z−10=40⇒y+z=50   ....(2)From equations (1) and (2), we haveA's age =x=(x+y+z)−(y+z)=(87−50) years =37 years