326 VALUATION, DEPRECIATION AND THE RATE-BASE 
EXPLANATION OF TABLE 19 
SiMpPLE INTEREST ON ONE DOLLAR FOR ONE DAY AND FOR ONE MONTH 
— 360 DAY YEAR 
This table has been calculated on the basis of a 360 day year 
with twelve months of thirty days each. The calculations have 
been carried to 12 decimal places. 
To obtain the interest on one dollar for any number of days 
or months, the figure for one day or one month at the interest 
rate required should be taken from the table and multiplied by 
the number of months or number of days involved. A com- 
bination of months and days can be obtained by two such simple 
multiplications and the addition of the multiplicands. 
Example. — (a) What is the simple interest at 53 per cent on 
$1 for 8 months and 23 days? Take from the “ Day ” column 
the figure for interest at 53 per cent and multiply by 23. Take 
from the ¢“ Month ”’ column the figure for interest at 53 per cent 
and multiply by 8. Add the results together. 
$o.000152777778 X 23 = $0.003513888889 
0.004583333333 X 8 = 0.036666666667 
$o.040180555556 
Answer = $o.0402. 
(b) What is the simple interest at 33 per cent on $1462.15 for 
3 months and ro days? Take from the “ Day” column the 
figure for interest on $1 at 31 per cent, multiply it by 10 and then 
by $1462.15. Take from the “ Month ” column the figure for 
interest on $1 at 31 per cent, multiply it by 3 and then by $1462.15 
Add the two results. 
$1462.15 X 0.000090277778 X 10 = $ 1.3200 
$1462.15 X 0.002708333333 X 3 = 11.8800 
$13.2000 
Answer = $13.2000.