Truck A has two single axles. One axle weighs 12,000 lb and the other weighs 23,000 lb. Truck B has an 8000-lb single axle and a 43,000-lb tandem axle. A rigid pavement is to be designed to provide a service life of 30 years. The modulus of subgrade reaction is determined to be 300lb/in^3. Reliability is 95%, the overall standard deviation is 0.45, the concrete's modulus of elasticity is million lb/in^2, and the drainage coefficient is 1.0. Which truck will cause more pavement damage on a rigid pavement with a 10-inch slab?

An external consultant recommends that a plant installs a bank of capacitors for power factor correction. this will reduce the peak electrical demand charges by an average of 93 kw every month. the plant current pays $13 per kw in peak demand charges. the capacitor bank will include 223 kw of fixed capacitors, and 183 of variable capacitors. the fixed capacitors cost $59 per kw, and the variable capacitors will cost $65 per kw. the consultant charges 21% of the equipment costs to install the capacitors. because this project will reduce the demand for the electric utility, they are prepared to provide a one-time rebate of $42 per kw of reduced demand. what is the simple payback period for this project (in years)?