The grounde of artes teaching the perfect vvorke and practise of arithmetike, both in whole nu[m]bers and fractions, after a more easie ane exact sort, than hitherto hath bene set forth. Made by M. Robert Recorde, D. in Physick, and afterwards augmented by M. Iohn Dee. And now lately diligently corrected, [and] beautified with some new rules and necessarie additions: and further endowed with a thirde part, of rules of practize, abridged into a briefer methode than hitherto hath bene published: with diverse such necessary rules, as are incident to the trade of merchandize. Whereunto are also added diuers tables [and] instructions ... By Iohn Mellis of Southwark, scholemaster.

A fourth deriued question out of this branch which is a Proofe of this last, and also of the other two going before.

ITem, how much money ought a Mer∣chant to deliuer after 8 lb in the 100 for 12 moneths that in 3 moneths I may gaine 8 lb — 12 s.

Answere. You maye also if you please

worke it by the Golden Rule of thrée at twice, firste saying if 3. moneths gaine 8. lb. what 12 months gaine? you shal finde 34 lb: Then say againe, if 8 lb— become of 100 lb what shall come of 34 lb—8 s? worke, and you shall finde: the answere to the question, whiche is 430 lb: and so muche ought the Merchant to deliuer.

But moste briefly it is aunswered by the Backer Rule of 5 numbers, where I argue thus, saying: if 100 lb be 12 monethes a gai∣ning of 8 lb: then but for 3 moneths terme, onely to take 8 lb — 12 s muste néedes be a good rounde summe: to worke it, sette your number thus, 100 — 12 — 8 — 3 — 8 ⅗: multiplying the firste into the second: and al∣so by 43 the product of the fift for your diui∣dend: and the third and fourth togither with 5 the Denominator of your Fraction, for your Diuisor: then diuide, and you shal find as before 430 lb: The true solution to your question.