







A price increase and a consumption decrease 
20140816 

sujan pose la question : If the price of petrol increases by 25% and Rajesh intends to spend only 15% more on petrol then by how much % should he reduce the quantity of petrol he buys? Penny Nom lui répond. 





Marine shipping  fuel consumption 
20060426 

Sandy pose la question : When a ship is 800 nautical miles from port its speed is reduced by 20%,
thereby reducing the daily fuel consumption by 42 tonnes and arriving in
port with 50 tonnes onboard. If the fuel consumption per hour is given
by the expression (0.136 + 0.001V^3) where V is speed in knots;
Estimate a) reduced consumption per day b) fuel onboard when speed reduced
c) normal consumption for 800 nautical mile voyage d) increase in steaming
time Stephen La Rocque lui répond. 





Fuel consumption 
20021111 

Guy pose la question : When a car is driven 'normally' the feul consumption is 7.5 per litres per 100km. On a particular journey the car was driven in 'hard' and the consumption changed to 9.1 litres per 100km. Fuel cost 80p per litre. Calculate:
a) The extra feul consumed. b) The extra cost of feul, in pounds, for the journey when the car was driven in 'hard'. Penny Nom lui répond. 





Conservation, consumption and population growth 
20010604 

Steve pose la question : I'm trying to quantify the relation between conservation/consumption and population growth. For instance let's consider California: The 2000 census states that California's population grew from 29,760* in 41990 to 33,871 in 42000. I want to find r or rate of growth per year. Based on the exponential growth formula for population growth: . . . Penny Nom lui répond. 





Marginal Propensity to Consume 
20010509 

Esther pose la question : The derivative of the national consumption function C = f(y) is called the ____________________. Judi McDonald lui répond. 





National consumption function 
20010509 

Brian pose la question : If consumption is $11 billion when disposable income is 0 and the marginal propensity to consume is dC/dy = 1/(2y+4)1/2+0.3(in billions of dollars), find the national consumption function. Harley Weston lui répond. 

