Math, asked by PrabhuAmar, 10 months ago

The average age of A and B is 20 years. If C were to replace A, the average age would be 19, and if C were to replace B, the average age would be 21. What are the ages of B and C?

Answers

Answered by waniyajeeyahoney
0

Step-by-step explanation:

A+B/2=20 A+B=40

B+C/2=19 B+C=38

C+A/2=21 C+A=42

BY SUBTRACTING A+B=40 AND B+C=38 WE GET A+B-B-C=40-38 A-C=2

BY ADDING A+C=42 AND A-C=2 WE GET 2A=44 A=22

A+C=42 C=42-22=20 C=20

A+B=40 B=40-22 B=18

A=22,B=18,C=20

option B

A+B=2*20;

C+B=2*19;

A+C=2*21;

By solving the above equations we get the solution

A+B/2=20 A+B=40---------1

C+B/2=19 C+B=38----------2

C+A/2=21 C+A=42----------3

BY SUBSTRACTING 1&2 A+B=40 AND B+C=38 WE GET A+B-B-C=40-38

A-C=2

NOW SOLVING A-C=2 & A+C=42

2A=44

A=22

SUBSTITUTE A=22 IN A-C=2

C=22-2

C=20

SUBSTITUTE C=20 IN B+C=38

B=38-C

B=38-20

B=18

Answered by shubh1729
1

Answer:

Average age of A and B = 20 years

A+B/2 = 20

A+B=40

Average age of C and B = 19 years

C+B/2 = 19

C+B=38

Average age of A and C =21 years

A+C/2 = 21

A+C=42

A+C-A-B=2

C-B=2

B+C+B-C=38-2

2B=36

B=18

C=20

A=12

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