Question

In how many parts can a rod of length 19.5m be broken into equal lengths of 65cm?
A. 20
B. 30
C. 3
D. 130

Answer 1

Hint: In this problem, first we need to convert the length of rod into centimeters. Next, divide the length of rod by the length of the broken piece of rod. The ratio of two quantities in the same unit is a unit less number that shows how many times one quantity is greater or smaller than another quantity.

Complete step by step answer:
We know that,
\[
  1m \to 100cm \\
  19.5m \to 19.5 \times 100cm \\
  19.5m \to 1950cm \\
\]
Now, divide the length of the rod (1950cm) by the length of the broken piece of rod (65cm) to obtain the number of parts as shown below.
\[
  {\text{Number of parts = }}\dfrac{{{\text{length of rod}}}}{{{\text{length of a piece of rod}}}} \\
  {\text{Number of parts = }}\dfrac{{1950}}{{65}} \\
   = 30 \\
\]

So, the correct answer is “Option B”.

Note: 1 meter is equivalent to 100 centimeters. Here, the units of the length of the rods are the same, so the number of parts will be unit less.