Answer :
Let's solve the question step-by-step.
Question 3:
A truck carries a load of 50 boxes; some are 20 kg boxes and the rest are 25 kg boxes. If the total weight of all boxes is 1175 kg, how many of each type are there?
Step-by-Step Solution:
1. Define Variables:
- Let [tex]\( x \)[/tex] be the number of 20 kg boxes.
- Let [tex]\( y \)[/tex] be the number of 25 kg boxes.
2. Write Equations:
We know that:
- The total number of boxes is 50:
[tex]\[ x + y = 50 \][/tex]
- The total weight of the boxes is 1175 kg:
[tex]\[ 20x + 25y = 1175 \][/tex]
3. Solve the System of Equations:
We have the following system of linear equations:
[tex]\[ \begin{cases} x + y = 50 \quad \text{(Equation 1)} \\ 20x + 25y = 1175 \quad \text{(Equation 2)} \end{cases} \][/tex]
4. Isolate One Variable:
From Equation 1, isolate [tex]\( y \)[/tex]:
[tex]\[ y = 50 - x \][/tex]
5. Substitute and Solve:
Substitute [tex]\( y = 50 - x \)[/tex] into Equation 2:
[tex]\[ 20x + 25(50 - x) = 1175 \][/tex]
6. Simplify and Solve for [tex]\( x \)[/tex]:
[tex]\[ 20x + 1250 - 25x = 1175 \][/tex]
[tex]\[ 20x - 25x + 1250 = 1175 \][/tex]
[tex]\[ -5x + 1250 = 1175 \][/tex]
[tex]\[ -5x = 1175 - 1250 \][/tex]
[tex]\[ -5x = -75 \][/tex]
[tex]\[ x = \frac{-75}{-5} \][/tex]
[tex]\[ x = 15 \][/tex]
7. Find [tex]\( y \)[/tex]:
Substitute [tex]\( x = 15 \)[/tex] back into the equation [tex]\( y = 50 - x \)[/tex]:
[tex]\[ y = 50 - 15 \][/tex]
[tex]\[ y = 35 \][/tex]
8. Conclusion:
Hence, the number of 20 kg boxes is [tex]\( 15 \)[/tex] and the number of 25 kg boxes is [tex]\( 35 \)[/tex].
Thus, the solution is [tex]\( 15 \)[/tex] boxes of 20 kg and [tex]\( 35 \)[/tex] boxes of 25 kg.
Question 3:
A truck carries a load of 50 boxes; some are 20 kg boxes and the rest are 25 kg boxes. If the total weight of all boxes is 1175 kg, how many of each type are there?
Step-by-Step Solution:
1. Define Variables:
- Let [tex]\( x \)[/tex] be the number of 20 kg boxes.
- Let [tex]\( y \)[/tex] be the number of 25 kg boxes.
2. Write Equations:
We know that:
- The total number of boxes is 50:
[tex]\[ x + y = 50 \][/tex]
- The total weight of the boxes is 1175 kg:
[tex]\[ 20x + 25y = 1175 \][/tex]
3. Solve the System of Equations:
We have the following system of linear equations:
[tex]\[ \begin{cases} x + y = 50 \quad \text{(Equation 1)} \\ 20x + 25y = 1175 \quad \text{(Equation 2)} \end{cases} \][/tex]
4. Isolate One Variable:
From Equation 1, isolate [tex]\( y \)[/tex]:
[tex]\[ y = 50 - x \][/tex]
5. Substitute and Solve:
Substitute [tex]\( y = 50 - x \)[/tex] into Equation 2:
[tex]\[ 20x + 25(50 - x) = 1175 \][/tex]
6. Simplify and Solve for [tex]\( x \)[/tex]:
[tex]\[ 20x + 1250 - 25x = 1175 \][/tex]
[tex]\[ 20x - 25x + 1250 = 1175 \][/tex]
[tex]\[ -5x + 1250 = 1175 \][/tex]
[tex]\[ -5x = 1175 - 1250 \][/tex]
[tex]\[ -5x = -75 \][/tex]
[tex]\[ x = \frac{-75}{-5} \][/tex]
[tex]\[ x = 15 \][/tex]
7. Find [tex]\( y \)[/tex]:
Substitute [tex]\( x = 15 \)[/tex] back into the equation [tex]\( y = 50 - x \)[/tex]:
[tex]\[ y = 50 - 15 \][/tex]
[tex]\[ y = 35 \][/tex]
8. Conclusion:
Hence, the number of 20 kg boxes is [tex]\( 15 \)[/tex] and the number of 25 kg boxes is [tex]\( 35 \)[/tex].
Thus, the solution is [tex]\( 15 \)[/tex] boxes of 20 kg and [tex]\( 35 \)[/tex] boxes of 25 kg.