Question

If 2 tons of snow fall in 1 minute, calculate the tons of snow fall in 3 hours.
a. 6
b. 36
c. 360
d. 3,600
e. 4,000

Answer 1

Hint: We will assume that x tons of snow fall in 3 hours. Then, we will convert 3 hours into minutes using the relation 1 hour = 60 minutes. And then by using the concept of ratio and proportion, we will relate the ton of snow fall to the time taken for the snow fall. Then simplifying the ratio, we get the value of the tons of snow fall in 3 hours.

Complete step-by-step answer:
We have been given in the question that, 2 tons of snow fall in 1 minute and we have been asked to find the tons of snow fall in 3 hours.
We will first assume the tons of snow fall in 3 hours as x tons.
Now, we will convert 3 hours into minutes. And we know that 1 hour = 60 minutes so,
$3\text{hours}=3\times 60\text{minutes}$
So, we get,
3 hours = 180 minutes
Hence, we get that the time taken for x tons of snow fall is 180 minutes.
Now, we will use the concept of ratio and proportion. We know that 2 tons of snow fall in 1 minute. And also, we have found the time for x tons of snow fall in terms of minutes as 180 minutes.
So, we can write the ratio of tons of snow fall to the time taken for the snow fall as,
$\dfrac{\text{tons}}{\text{min}}\text{=}\dfrac{2}{1}\text{=}\dfrac{\text{x}}{\text{180}}$
On cross multiplying the above ratio, we will get,
$\begin{align}
  & 2\times 180=1\times x \\
 & 360=x \\
\end{align}$
That is, we get x = 360 tons.
Therefore, we get that the tons of snow fall in 3 hours is equal to 360 tons.

So, the correct answer is “Option (c)”.

Note: The most common mistake that the students make while solving this question is that they forget to convert the hours into minutes and directly form the ratio as $\dfrac{\text{tons}}{\text{min}}\text{=}\dfrac{2}{1}\text{=}\dfrac{\text{x}}{3}$ and as a result will get the answer as 6, which is option (a) and it is the wrong answer. So, the students must remember that, all the quantities taken must have the same unit.
Also, the students can convert 1 minute into hours and then proceed and they will get the same answer. In order to convert minutes into hours, we have to divide it by 60.