Elementary arithmetic, with brief notices of its history... by Robert Potts.

27

XVI.
1. He adds ~35 to every ~100 of the purchase, which makes ~135 the selling
price of ~100: and 10 per cent. for prompt payment on ~135 is ~13i, which deducted from ~135 leaves ~111~, leaving a gain of ~11~ on ~100 capital.
2. The present worth of ~210 is ~200; his gain is the differenec of 20020
and the prime cost, ~170, which is ~30g~0.
3. Prime cost ~100, with gain ~15, gives ~115 selling price in 4 months, and in
12 months a sale of ~345 is realised with ~45 profit. Prime cost ~100 with gain
~20 gives selling price ~120 in 6 months, and in 12 months a sale of ~240 is realised
with a gain of ~40.
4. The present value of the bill is ~600, which if put out to compound interest
at 4~ per cent. per annum, payable quarterly, would amount to ~627 9s. 2~d. at the
end of the year. 5. Making the deduction by true discount, the cash price should
be 11 s.
6. The manufacturer's cost of an article is ~100.
Manufacturer adds 10 per cent. and sells to wholesale dealer for ~110.
Wholesale dealer adds 15 per cent. to ~110, and sells to retail dealer for ~1262.
Retail dealer adds 30 per cent. to ~126~, and sells to customer for ~1642o.
Thus what was made for ~100 is sold at last for a profit of ~64 9s., or ~54 9s. to
the two middle men.
XVII.
1. The 3 horses must be sold for ~119 2s. 7d. to gain 10 per cent. on the prime
cost of them.
2. Here ~100 paper money=~80 gold, and hence ~6 10s. gold is equivalent to
~8 2s. 6d. paper money.
The purchase was made for ~6 10 0 paper money.
Deducting 5 per cent. 0 6 6
Leaves sum to be paid in paper 6 3 6
But value in gold offered was 8 2 6 in paper money.
Change in paper money received ~1 19 0
3. Before the strike: 52 weeks' wages at 15s. =-780s. Od.
21- per cent. on yearly wages 19s. 6d.
52 weeks' expense of living = 760s. 6d.
After the strike: 52 weeks' wages at 17s. =884s. Od.
Expenses raised in ratio of 6 to 7 =887s. 3d.
Instead of saving, he is in debt = 3s. 3d.
I.1 other words, he was a poorer man by ~1 2s. 9d. a year, after the strike than he
was belore it.
4. ~540. of 3 per cent. stock. 5. At 12s. 3 —d. per gallon. 6. The gain is
25 per cent.; the loss is 20 per cent. The difference arises from the fact that the
gain and loss are calculated from different amounts of capital, the former from ~88,
the latter from ~110.
7. ~43*7 gained. 8. Suppose the value to be ~100, deducting banker's discount at 10 per cent. leaves ~90 to be paid 6 months hence. If the ~90 be paid
3 months before due, true discount ought to be deducted; if 3 months after,.3 months' interest ought to be added to the sum. 9. At 6a2d.. per oz. Avoirdupois.