A boy spent one-fifth of his money on transportfare,one-tenth on food and two-seventh of the remainder on book and he was left with #900.what is the original money?

m - m/5 - m/10 - (7m/10 * 2/7) = 900

m - 2m/10 - m/10 - 2m/10 = 900

5m / 10 = 900