If the sum of two numbers is 55 and the H.C.F. and L.C.M of these numbers are…
2024
If the sum of two numbers is 55 and the H.C.F. and L.C.M of these numbers are 5 and 120 irrespectively than the sum of the reciprocals of the numbers is equal to:
- A.
1/120
- B.
13/120
- C.
13/60
- D.
11/120
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Show answer & explanation
Correct answer: D
To find the sum of the reciprocals of two numbers when their sum, H.C.F., and L.C.M. are known, you can use a simple algebraic relationship.
The Formula
Let the two numbers be x and y. We want to find the sum of their reciprocals:
Sum of reciprocals = 1/x + 1/y = (x + y) / (x * y)
Where:
(x + y) is the sum of the numbers.
(x * y) is the product of the numbers, which is also equal to H.C.F. * L.C.M.
Step-by-Step Calculation
Identify the given values:
Sum of numbers (x + y) = 55
H.C.F. = 5
L.C.M. = 120
Calculate the product of the numbers:
Product (x * y) = H.C.F. * L.C.M. = 5 * 120 = 600
Calculate the sum of reciprocals:
Sum of reciprocals = (Sum of numbers) / (Product of numbers)
Sum of reciprocals = 55 / 600
Simplify the fraction by dividing both numerator and denominator by 5:
Sum of reciprocals = 11 / 120