Willsfords arithmetick, naturall, and artificiall: or, decimalls. Containing the science of numbers, digested in three books. Made compendious and facile for all ingenious capacities, viz: merchants, citizens, sea-men, accomptants, &c. Together with the theorie and practice united in a sympathetical proportion betwixt lines and numbers, in their quantitites and qualities, as in respect of form, figure, magnitude and affection: demonstrated by geometrie, illustrated by calculations, and confirmed with variety of examples in every species. / By Thomas Willsford, Gent.

Question 5. Four men joyned their stocks together, as A, B, C, & D, whereof A ventured 40 L. B 160 L. C 100 L. D 280 L. by misfortune they were all losers: upon which they fell at difference, at severall times, and broke off from this society, when D had lost 20 L. C 10 L. & B 30 L. A continued the trade 12 moneths, and lost 8 L. how long were all their stocks continued at that rate or proportion?

In all questions of

		L.		M D
L		30	B	11 7
8	480	10	C	6 0
		20	D	4 8

this nature, the dou∣ble proportion must be made one, as here in this it is A, whose stock was 40 L. the time 12 moneths, the product 480; his losse was 8 L. for the first terme, so the proportion will be, as 8 L. losse is unto the product of the time and principle, that is here 480; so shall each particular losse be proportionable unto the product of his time and principle, and being it con∣tains them both, and the adventure known, divide that fourth proportionall found by his principle or

stock, and the quotient will discover the true time; as in this last Example, 480 multiplied by 30 L. (the losse which B sustained) the product will be 14400, which divided by 8 L. the first terme, the quotient will be 1800 the true product of time and principle; therefore 1800 divided by 160 L. the adventure of B, the second quotient will be 11 ¼ moneths, that is, 7 dayes in all 45 weeks; and so long time did B con∣tinue his stock in the same company; in this man∣ner, C that lost 10 L. will be discovered 6 moneths, and D that lost 20 L. kept in this society but 4 mon: and 8 dayes, as in the preceedent Example is evi∣dent, where 68 L. was lost in all.

Any question of this kinde, must be tried by a contrary way; as with each mans adventure, his time, and the losse of one mans stock, to finde the others: and so likewise in any other question where∣in gain is made: and no more questions will I shew here in this Paragraph, lest that I should lose more time, than the Reader shall gain benefit.