Question

divide 20 into two parts so that the sumbpf their reciprocal is 4/15

Answer 1

Let the two parts be x and y

So according to the question
Total = 20
So x + y = 20(1)
And 1/x + 1/y = 4/15(2)
solve (1) and (2)
u will get the answers ....

Answer 2

Let one number be x.

Then the other number will be 20-x.

Given that the sum of their reciprocal =4/15

1/x + 1/20- x = 4/15

20 - x + x = 4(x(20 - x)) /15^2

300 = 4(20x - x^2)

300 = 80x - 4x^2

4x^2 - 80x + 300 = 0

x^2 - 20x + 75 = 0

x^2 - 15x - 5x + 75 = 0

x(x - 15) - 5(x - 15) = 0

(x - 5)(x - 15) = 0

x = 5(or)x = 15.


Therefore the numbers are 5 and 15.


Hope this helps!