A machine that cost £35,000 is operated 8 hours a day in a 5-day week but one hour each day is used for test purposes. For use o
f the machine there are three scales of charges, the first at the rate of £5 an hour for private use, the second at £15 an hour for research work and the third at £40 an hour for commercial work. It is estimated that the number of hours charged at the first, second and third rates are in ratios 4:2:1. What percentage of total receipts do receipts from commercial work represent?
Place the right angle at the origin. Short leg on x-axis. The forth corner of the square is the point on the hypotenuse where the line y = x intersects. (Draw a diagram!) In this case the hypotenuse is y = -4x/3 + 8 x = -4x/3 + 8 7x/3 = 8 7x = 24 x = 3.428571429
There are a total of 31 fish in the tank. Therefore, the probability of it being a goldfish is 24/31 or about 77.4%, since there are 24 goldfish. The probability of it being an angel fish is 2/31 or about 6.45%, for the same reason as before.
