Answer:
Phoebe's age = 24 years.
Step-by-step explanation:
Given:
Highest Common Factor and Lowest Common Multiple of the ages are 3 and 168 respectively.
Phoebe is 3 years older than Jody.
To find:
The age of Phoebe = ?
Solution:
Here, We have two numbers whose
HCF = 3 and
LCM = 168
Let the age of Phoebe = P years and
Let the age of Jody = J years
As per given statement:
[tex]P = J + 3 ...... (1)[/tex]
Let us learn about the property of LCM and HCF of two numbers.
The product of LCM and HCF of two numbers is equal to the product of the two numbers themselves.
LCM [tex]\times[/tex] HCF = P [tex]\times[/tex] J
[tex]\Rightarrow P\times J = 3 \times 168 \\\Rightarrow P\times J = 504[/tex]
Putting the value of P from equation (1):
[tex]\Rightarrow (J+3)\times J = 504\\\Rightarrow J^2+3J-504 = 0\\\Rightarrow J^2+24J-21J-504 = 0\\\Rightarrow J(J+24) - 21(J+24) = 0\\\Rightarrow (J - 21)(J+24) = 0\\\Rightarrow J = 21, -24[/tex]
Negative value for age is not possible So, Jody's age = 21 years
Using equation (1):
Phoebe's age = 21 + 3 = 24 years.
