The LCM of two numbers is 28 times their HCF and the sum of their LCM and HCF is 493. The difference of the two numbers is 51. If s is the sum of the two numbers, then what is the sum of digits of s?
The LCM of two numbers is 28 times their HCF and the sum of their LCM and HCF is 493. The difference of the two numbers is 51. If s is the sum of the two numbers, then what is the sum of digits of s? Correct Answer 16
Given:
The LCM of two numbers = 28 × HCF of two numbers
Sum of LCM and HCF = 493
Difference between numbers = 51
Concept:
LCM:- The least common multiple of two numbers is the smallest non zero common number which is a multiple of both the numbers
HCF:- The highest common factor of two or more numbers is the greatest factor that divides the numbers.
LCM × HCF = Product of Numbers
Calculation:
Let the numbers be X and Y and HCF and
LCM of the numbers be p and q respectively
According to the question
q = 28p and p + q = 493
On solving these, we get
⇒ p + 28p = 493
⇒ 29p = 493
⇒ p = 17 and q = 476
Again, According to the concept used
⇒ XY = 476 × 17 = 8092 ----(1)
⇒ X - Y = 51 ----(2)
⇒ X + Y = s ----(3)
On solving the equations (1) and (2), we get
⇒ X2 - 51X - 8092 = 0
⇒ X = 119, and Y = 68
⇒ By equation (3)
⇒ X + Y = s
⇒ s = 119 + 68 = 187
The sum of the digits of s = 1 + 8 + 7 = 16
∴ The required result will be 16.