Question

the sum of two no. is 15 if reciprocal is 3/10 find no.

Answer 1

Answer:

let the two numbers be A and B

=>A+B=15                      .............(1)

and

1/A +1/B=3/10

⇒(A+B)/AB = 3/10

from (1)

(A+B)/AB = 15/AB

⇒15/AB = 3/10

⇒AB = 50        ............(2)

solving (1) and (2)

A = 10 and B = 5

or

A = 5 and B = 10

Answer 2

≡QUESTION≡

The sum of two numbers is 15, if the sum of the reciprocals is 3/10 find the number.

                                                                                           

║⊕ANSWER⊕║

Let one of the numbers be x.

Other number is (15 - x)

Sum of their reciprocals = 3/10

1/x + 1/(15 - x) = 3/10

(15 ) / (15x - x2) = 3/10

150 = 45x - 3x2

3x2 - 45x + 150 = 0

x2 - 15x + 50 = 0

(x - 10)(x - 5) = 0

x = 10 or 5

∴ The numbers are 10 and 5.