Given:
The number of cycles is, <em>n</em> (s) = 7.
The number of wheels in the cycle is, <em>n </em>(sw) = 2.
The number of cars is, <em>n</em> (c) = 15.
The number of wheels in the car is, <em>n</em> (cw) = 4.
The obective is to find the total number of wheels.
The total number of wheels is,
Hence, there are 74 wheels in the block.
If there are <em>x</em> bicycles and <em>y </em>cars, the equatioin will be,
Hence, the number of wheels for x bicycles and y cars is 2x+4x.