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

11
12. If ~960 put out for 6 years at simple interest amount to
~1248; what is the rate per cent. per annum?
13. In how many years will ~800 become ~1088 at 4 per cent.
simple interest?
V.
1. What sum of money is that which amounts in 3 months to
~249. 9s., and in 9 months to ~256. 3s. 8c., and at what rate of
interest is it lent?
2. What was the interest of the national debt of Great Britain and
Ireland for one hour, calculated at the rate of 3 per cent. per annum,
if the amount in 1872 was ~730,986,800?
3. What must be the rate of interest per cent. per annum, in order
that the interest of fifty American dollars may be one cent. per diem?
4. What is the interest on 30~029 rupees, 4 annas, 6 pice, at 4! per
cent.? Give the result in English money when the rupee is worth
2s. 1i-d., the rupee containing 16 annas, and the anna 12 pice.
VI.
1. Explain the distinction between true discount and banker's
discount. Does the creditor or the debtor gain by computing interest
instead of discount?
2. Find the discount on ~100 due one year hence, if money bear
interest at 5 per cent. per annum. Calculate the interest on this
discount for the same time, and shew that it is equal to the difference
between the interest and the discount of ~100.
3. Find the present worth of ~250 due 2~ years hence at 5 per
cent. per annum; and shew that the discount of the given sum is equal
to the present worth for the same time and at the same rate of interest.
4. A person agrees to discount a bill for ~675 payable in 40 days
at the rate of 2- per cent. per annum interest. How much does he pay?
5. What must be the rate of interest, in order that the discount on
~2573 payable at the end of one year and seventy-three days may be
~93?
6. Shew that the interest on ~266. 13s. 4d. for three months, at
41 per cent. per annum, is equal to the discount of ~83 for 15 months
at 3 per cent. per annum.
7. If the discount on a bill due 8 months hence at 2_- per cent. per
annum be ~12. Os. lld., what is the amount of the bill?
8. What sum of money must be placed out at simple interest
for 5 years at 4~ per cent. that the amount may be ~1000?
9. What is the present worth of ~1275, payable as follows:
~90 in 3 months, ~735 in 7 months, and the rest in 11 months, if
money bear interest at 5 per cent. per annum?
10. A man having lent ~2,500 at 5 per cent. interest, payable
half-yearly, wishes to receive his interest in equal portions monthly,
and in advance; how much ought he to receive every month?