Question

Mohini has $30m$ cloth and she wants to make some shirts for her son. If each shirt requires $2m$ $30cm$ cloth, how many shirts can be made and how much length of cloth will be left?

Answer 1

Hint: Convert all the units into one unit. Here, you can convert centimetre to metre and proceed to your calculations. For a number of shirts; remember, it must be a whole number since shirts can never be in decimals either it be whole or none.

Complete step by step solution:
Total length of cloth that Mohini has=$30$m
Length of cloth required for each shirt=$2$m$30$ cm
Now, we will convert centimetre to metre for ease of calculation.
As we know, $1$m$=100$cm
Using unit method,
$1$cm$=\dfrac{1}{100}$m
$30$cm$=\dfrac{1}{100}30$m$=0.3$m
We get$30cm$equal to$0.3m$ with the help of conversion of units of measurement and unit method.
Therefore, length of cloth required for each shirt in metre is $2m+0.3m=2.3m$
Number of shirts made =$\dfrac{\text{total length of cloth}}{\text{length of cloth of each shirt}}$
Number of shirts=n= $\dfrac{30}{2.3}=13.04$
Since the number of shirts cannot be a fractional quantity, it must be a natural/whole number.
Therefore, $n<13.04$ n must be the greatest natural number less than $13.04$. Thus n=$13$.
$13$ Shirts have been made by Mohini for her son.

Length of cloth left=Total length of cloth-length of cloth required for $13$ shirts
Length of cloth required for $13$ shirts = $13\times $ length of cloth for one shirt
$=13\times 2.3$
=$29.9$m
Length of cloth left= $30-29.9$
$=0.1$m
Conversion of unit of measurements; $1$m$=100$cm
$0.1m=0.1\times 100=10cm$
Length of cloth left is $10$ cm or $0.1$m.

Note:
You can also convert metre into centimetre and then proceed with your calculation. It depends on you which conversion you have to take to solve your question.
You can take $30$ m of cloth as $3000$ cm and length of cloth required can be taken as $230$ cm and solve your question to get to your answer, you will get the same result but in centimetre.