The process may be written as below:

Suppose it required to take 13 parts out of a hundred from £56. 13. 7½.

Let it be required to take 2½ parts out of a hundred from £3 12s. The result, by the same rule is

£3 12s. × 2½ , or 123 £3 12s. × 5 ;
100200

so that taking 2½ out of a hundred is the same as taking 5 parts out of 200.

EXERCISES.

Take 7⅓ parts out of 53 from £1 10s.

Answer, 4s. 1 129 d.
159