Pls i need help with this Solve using Matlab three problems:

One using the combination formula

One using the permutation of n objects formula

One using the permutation of r objects out of n objects

You can make up your own questions

Machinery that is a key part of the process and without which the plant or process cannot function is classifed as: (clo4) a)-critical machinery b)-essential machinery c)-general purpose machinery d)-none of the specified options.

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]

The sum of the normal stresses does not change as the stress state rotates through an angle. a)-trune b)- false