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

20

p)er ounce; what is the worth of a piece of silver of the same weight.at ~2. 14s. 6d. per pound?
4. If gold be at a premium of 20 per cent., and a person buys
goods marked 135 dollars, and offers gold to the amount of 135
dollars, what change ought he to receive in notes, 5 per cent. being
abated for ready payment?
5. A gold coinage, of which each piece weighs 132 grains, is
alloyed with a metal of one-twelfth the value of gold; and another,
each piece of 104 grains alloyed with a metal one tenth the value of
gold; find the relative value of the two pieces, if a thirteenth part of
each coin be alloy.
6. Find the proportion of the values of a gold coin and a silver
coin, if 13 gold coins together with 12 silver coins are worth 3 times
as much as 3 gold coins and 40 silver.
XIX.
1. If ~39 are equal to 1000 francs, the French hectolitre equals
344 quarters. Is corn cheaper in England at 39 shillings a quarter,
or in France at 17 francs the hectolitre?
2. If 8000 metres be equal to 5 miles, and if a cubic fathomni of
water weigh six tons, and a cub.]ic metre of water 1000 kilogranmmes;
find the ratio of a kilogramme to a pound Avoirdupois.
3. A block of mahogany in the form of a rectangular parallelopiped measures along its edges 181- feet, 5-1 feet, and 3 feet respectively; determine its value on the supposition that a cubical block of
the same wood measuring 7 inches along the edge is worth 3s. 6d.
4. A beam is 5ft. 6in. long, lOin. wide and 8in. thick, and weighs
8cwt. lqr.; find the length of another beam the end of which is 100
square inches which shall weigh one ton.
5. If a piece of land 375ft. 6in. long, and 75ft. 9in. in breadth,
cost ~118. 2s. 6d.; what will be the price of a piece of similar land.278ft. 9in. long and 157ft. broad?
6. If granite be sold at 2s. 7-d. the cubic yard; find the price of
235 blocks of it, each of which contains 431 cubic feet.
XX.
1. A piece of work can be done in 50 days by 35 men working all
together; and if after working together for 12 days 16 of the nien
were to leave the work, find the number of days in which the remaining men could finish it.
2. The expense of 19 workmen for 35 weeks is ~310. 10s.; how
many weeks must 43 workmen labour for ~555. 7s.?
3. A person contracts to do a piece of- work in 30 days and
employs 15 men upon it; the work is half finished in 24 days: how
-many additional workmen must he then introduce in order to perform
the contract?