The sum of ages of A and B is 72years,B and C is 65years,A and C is 41 years then the sum of A,B and C is____
Answers
Answer:
The sum of the ages of A, B and C is 89 years.
Step-by-step explanation:
Given :
- The sum of ages of A and B is 72 years
- The sum of ages of B and C is 65 years
- The sum of ages of A and C is 41 years
To find :
The sum of ages of A,B and C
Solution :
Let
- the age of A be x years
- the age of B be y years
- the age of C be z years
⇾ The sum of ages of A and B is 72 years.
x + y = 72 ➙ (1)
⇾ The sum of ages of B and C is 65 years.
y + z = 65 ➙ (2)
⇾ The sum of ages of A and C is 41 years.
x + z = 41 ➙ (3)
Subtract equation (2) from equation (1);
x + y - (y + z) = 72 - 65
x + y - y - z = 7
x - z = 7 ➙ (4)
Add equations (3) and (4);
x + z + x - z = 41 + 7
2x = 48
x = 48/2
x = 24 years
∴ The age of A is 24 years.
Substitute x = 24 in equation (1);
x + y = 72
24 + y = 72
y = 72 - 24
y = 48 years
∴ The age of B is 48 years.
Substitute x = 24 in equation (3);
x + z = 41
24 + z = 41
z = 41 - 24
z = 17 years
∴ The age of C is 17 years
➣ The sum of the ages of A, B and C
= x + y + z
= 24 years + 48 years + 17 years
= 89 years
Step-by-step explanation:
given,
1)sum of ages of A and B = 72years
= A+B = 72years
2) sum of ages of B and C = 65years
= B+C = 65years
3) sum of ages of A and C = 41years
= A+C = 41 years
.: adding all equations
= A+B+B+C+A+C = 72years+65years+41years
= 2A+2B+2C = 178years
= 2(A+B+C) = 178years
= A+B+C = 178/2 = 89
.: sum of ages of A,B,C = 89years