4. An automobile company uses three types of steel [tex]\( s_1, s_2, \)[/tex] and [tex]\( s_3 \)[/tex] for producing three types of cars [tex]\( c_1, c_2, \)[/tex] and [tex]\( c_3 \)[/tex]. Steel requirements (in tons) for each type of car are given below:

[tex]\[
\begin{array}{c|ccc}
& \multicolumn{3}{c}{\text{Cars}} \\
\text{Steel} & c_1 & c_2 & c_3 \\
\hline
s_1 & 2 & 3 & 4 \\
s_2 & 1 & 1 & 2 \\
s_3 & 3 & 2 & 1 \\
\end{array}
\][/tex]

Determine the number of cars of each type which can be produced using 29, 13, and 16 tons of steel of three types respectively.



Answer :

To determine the number of cars of each type [tex]\( c_1, c_2, \)[/tex] and [tex]\( c_3 \)[/tex] that can be produced using the given amounts of steel [tex]\( s_1, s_2, \)[/tex] and [tex]\( s_3 \)[/tex], we need to set up a system of linear equations based on the steel requirements and the available amounts of each type of steel.

Given:
- The steel requirements for each type of car:
- [tex]\( c_1 \)[/tex]: 2 tons of [tex]\( s_1 \)[/tex], 1 ton of [tex]\( s_2 \)[/tex], 3 tons of [tex]\( s_3 \)[/tex]
- [tex]\( c_2 \)[/tex]: 3 tons of [tex]\( s_1 \)[/tex], 1 ton of [tex]\( s_2 \)[/tex], 2 tons of [tex]\( s_3 \)[/tex]
- [tex]\( c_3 \)[/tex]: 4 tons of [tex]\( s_1 \)[/tex], 2 tons of [tex]\( s_2 \)[/tex], 1 ton of [tex]\( s_3 \)[/tex]

- The available amounts of each type of steel:
- [tex]\( s_1 \)[/tex]: 29 tons
- [tex]\( s_2 \)[/tex]: 13 tons
- [tex]\( s_3 \)[/tex]: 16 tons

We can translate these requirements into the following system of equations:

1. For [tex]\( s_1 \)[/tex] (total of 29 tons):
[tex]\[ 2c_1 + 3c_2 + 4c_3 = 29 \][/tex]

2. For [tex]\( s_2 \)[/tex] (total of 13 tons):
[tex]\[ c_1 + c_2 + 2c_3 = 13 \][/tex]

3. For [tex]\( s_3 \)[/tex] (total of 16 tons):
[tex]\[ 3c_1 + 2c_2 + c_3 = 16 \][/tex]

We now solve this system of equations:

1. Start with the given system:
[tex]\[ \begin{cases} 2c_1 + 3c_2 + 4c_3 = 29 \\ c_1 + c_2 + 2c_3 = 13 \\ 3c_1 + 2c_2 + c_3 = 16 \end{cases} \][/tex]

2. We solve this system using, for example, the method of substitution or elimination:

After solving, we find that:
[tex]\[ c_1 = 2 \][/tex]
[tex]\[ c_2 = 3 \][/tex]
[tex]\[ c_3 = 4 \][/tex]

Thus, the number of cars of each type that can be produced using 29 tons of [tex]\( s_1 \)[/tex], 13 tons of [tex]\( s_2 \)[/tex], and 16 tons of [tex]\( s_3 \)[/tex] are:

- [tex]\( c_1 = 2 \)[/tex] cars
- [tex]\( c_2 = 3 \)[/tex] cars
- [tex]\( c_3 = 4 \)[/tex] cars