Cars, Assemble!
Cars, Assemble!

Cars, Assemble!

Learning Exercise

While completing Cars, Assemble!, you'll learn 2 concepts



There are two different types of numbers in C#:

  • Integers: numbers with no digits behind the decimal separator (whole numbers). Examples are -6, 0, 1, 25, 976 and 500000.
  • Floating-point numbers: numbers with zero or more digits behind the decimal separator. Examples are -2.4, 0.1, 3.14, 16.984025 and 1024.0.

The two most common numeric types in C# are int and double. An int is a 32-bit integer and a double is a 64-bit floating-point number.

Arithmetic is done using the standard arithmetic operators. Numbers can be compared using the standard numeric comparison operators and the equality (==) and inequality (!=) operators.

C# has two types of numeric conversions:

  1. Implicit conversions: no data will be lost and no additional syntax is required.
  2. Explicit conversions: data could be lost and additional syntax in the form of a cast is required.

As an int has less precision than a double, converting from an int to a double is safe and is thus an implicit conversion. However, converting from a double to an int could mean losing data, so that requires an explicit conversion.

If Statements

In this exercise you must conditionally execute logic. The most common way to do this in C# is by using an if/else statement:

int x = 6;

if (x == 5)
    // Execute logic if x equals 5
else if (x > 7)
    // Execute logic if x greater than 7
    // Execute logic in all other cases

The condition of an if statement must be of type bool. C# has no concept of truthy values.


In this exercise you'll be writing code to analyze the production of an assembly line in a car factory. The assembly line's speed can range from 0 (off) to 10 (maximum).

At its lowest speed (1), 221 cars are produced each hour. The production increases linearly with the speed. So with the speed set to 4, it should produce 4 * 221 = 884 cars per hour. However, higher speeds increase the likelihood that faulty cars are produced, which then have to be discarded.

You have three tasks.

1. Calculate the success rate

Implement the (static) AssemblyLine.SuccessRate() method to calculate the ratio of an item being created without error for a given speed. The following table shows how speed influences the success rate:

  • 0: 0% success rate.
  • 1 to 4: 100% success rate.
  • 5 to 8: 90% success rate.
  • 9: 80% success rate.
  • 10: 77% success rate.
// => 0.77

2. Calculate the production rate per hour

Implement the (static) AssemblyLine.ProductionRatePerHour() method to calculate the assembly line's production rate per hour, taking into account its success rate:

// => 1193.4

Note that the value returned is a double.

3. Calculate the number of working items produced per minute

Implement the (static) AssemblyLine.WorkingItemsPerMinute() method to calculate how many working cars are produced per minute:

// => 19

Note that the value returned is an int.

Last updated 31 May 2023
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