Let the required no. be x.
Then its reciprocal be = 1/x.
According to the question,
x + (1/x )= 10/3
(x^2 + 1)/x = 10/3
3x^2 + 3 = 10x
3x^2- 10x + 3 = 0
3x^2- 9x - x + 3 = 0
3x (x-3) - 1 (x-3) = 0
3x - 1 = 0 or x - 3 = 0
x = 1/3 or x = 3.
... the reqiured number is 3