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

27
'8 kings of the Ostrogoths, during 92 years; and lastly under 22
lombardian kings during 206 years?
XXVII.
1. How long would it require to count 800 millions of money, at
tlhe rate of ~100 a minute, supposing the accountant to be employed
six days in the week and ten hours daily?
2. If 4 artillerymen can fire a gun 48 times, and 5 men 54 times
in an hour, how much longer time will be required for firing 32448
shots from 26 guns, when there are 4 men to each gun, and when
there are 5 men?
3. If 6 companies of 54 soldiers each fire 6804 shots in 3 hours,
how many shots will 8 companies of 81 men each fire at the same rate
in 2 hours?
4. A regiment contains 1000 men, of which 50 are officers, how
many men are there to each officer?
5. The population of the county of Middlesex increased from
1886576 in 1851 to 2206485 in 1861; what was the average yearly
rate per cent. of increase in the ten years?
6. An article which costs 12s. 6d. will last 6 months, and another
which costs 15s. will last 9 months; which is the cheaper of the two?
and how much in a year?
XXVIII.
1. If a clock gain 12 minutes in a day, what is the gain in one
minute?
2. How many times will a pendulum vibrate in 24 hours that
makes 5 vibrations in 2 seconds?
3. Express 59~ 27' 30" of longitude, in hours, minutes, and
seconds of time; and conversely.
4. On 21 June the sun rises 3hrs. 45m. a.m., and sets 8hrs. 18min.
p.m.; and on 21 December the sun rises at 8hrs. 6min. a.m., and sets
3hrs. 51 min. p.m. in the latitude of London; find the difference in
the lengths of the 21st June and 21st December.
5. The transit of the planet Venus across the sun's disk happened
on the morning of 9th December, 1874; the first contact at ingress
began lhr. 45min. 58sec. a.m., Greenwich mean time, and the last
contact at egress ended at 6hrs. 26min. 54sec. a.m. How long was
the planet in crossing over the sun's disk?
XXIX.
1. In how many weeks can a journey of 12600 miles be completed
by travelling six days each week at the rate three miles an hour and
seven hours each day?
2. If a man travel 300 miles in 10 days when the day is 12 hours
long, in how many days can he travel 800 miles when the day is 16
hours long?