A maximum of how many pieces of 12.6 cm can be cut from a 857 cm long rod?
Aptitude
Decimal Fraction
Difficulty: Easy
Choose an option
-
A58
-
B62
-
C64
-
D68
Answer
Correct Answer: 68
Explanation
## Concept & Formula
To find the maximum number of whole pieces that can be obtained, perform integer division (floor division) of the total length by the piece length.
$$ \text{Number of pieces} = \lfloor \frac{\text{Total Length}}{\text{Piece Length}} \rfloor $$
## Step-by-Step Solution
* **Given:**
Total length of the rod = 857 cm
Length of each piece = 12.6 cm
* **Calculation:**
Set up the division:
$\text{Number of pieces} = \frac{857}{12.6}$
Multiply both the numerator and denominator by 10 to clear the decimal:
$\text{Number of pieces} = \frac{8570}{126}$
Simplify the fraction by dividing by 2:
$\frac{4285}{63}$
Perform long division:
$4285 \div 63 = 68.015...$
Since we can only cut whole pieces, truncate the decimal value to the nearest lower integer.
$\text{Number of pieces} = 68$
## Exam Strategy & Shortcut
Use fast multiplication and estimation.
$12.6 \times 60 = 756$
Remaining length = $857 - 756 = 101$
Now find how many times 12.6 goes into 101:
$12.6 \times 8 = 100.8$
Total whole pieces = $60 + 8 = 68$. This eliminates long division entirely.
## Common Pitfall
Students sometimes round up to the nearest integer if the decimal fraction is high. In cutting/partitioning problems, you can never round up because you cannot create a piece out of missing material.
## Final Answer
**Therefore, the correct answer is 68.**