There are two consecutive number such of their reciprocals is 1/240?
**Finding the Consecutive Numbers**
Let's assume the two consecutive numbers as x and x+1.
**Setting up the Equation**
According to the problem, the reciprocals of these two numbers should sum up to 1/240. So, we can set up the equation as follows:
1/x + 1/(x+1) = 1/240
**Solving the Equation**
To solve this equation, we need to clear the denominators. Multiplying every term by the product of the denominators will eliminate the fractions.
240(x+1) + 240x = x(x+1)
Now, let's simplify the equation:
240x + 240 + 240x = x^2 + x
480x + 240 = x^2 + x
Rearranging the equation:
x^2 + x - 480x - 240 = 0
x^2 - 479x - 240 = 0
**Using the Quadratic Formula**
To solve this quadratic equation, we can use the quadratic formula:
x = (-b ± √(b^2 - 4ac)) / 2a
Here, a = 1, b = -479, and c = -240.
x = (-(-479) ± √((-479)^2 - 4(1)(-240))) / (2(1))
x = (479 ± √(229441 + 960)) / 2
x = (479 ± √230401) / 2
**Calculating the Values of x**
Now, let's calculate the two possible values of x using the quadratic formula:
x₁ = (479 + √230401) / 2 ≈ 479.999
x₂ = (479 - √230401) / 2 ≈ -478.999
Since the numbers are consecutive, they cannot be negative. Therefore, the value of x = 479.999 is not valid.
**Finding the Consecutive Numbers**
So, the only valid value is x = 480. The two consecutive numbers are 480 and 481.
Therefore, the two consecutive numbers such that their reciprocals sum up to 1/240 are 480 and 481.