Question

If three fire-fighters can clear $ 240 $ meters of a fire trail in two days, how many metres of fire trail can be cleared by four fire-fighters in three days, working at the same rate?

Answer 1

Hint: Identify the known and unknown ratios and set up the ratio and proportion and solve accordingly. In these ratio and proportion types of questions, follow the given data step by step and find the correlation between the knowns and unknowns.

Complete step-by-step answer:
Given that the three firefighters $ \dfrac{{120}}{3} = 40 $ s can clear $ 240 $ meters of a fire trail in two days
Therefore, $ \dfrac{{240}}{2} = 120 $ meters in $ 1 $ day
And also, one firefighter can clear $ \dfrac{{120}}{3} = 40 $ in one day.
Now, four firefighters can clear $ = 40 \times 40 = 160 $ meters in one single day.
Therefore, in three days four fighters can clear $ = 160 \times 3 = 480 $ meters.
This is the required solution.
So, the correct answer is “ 480 meters”.

Note: Always read the question twice and frame the word statement in the mathematical form. Segregate all the known and unknown terms and form the corresponding ratios and the proportions accordingly. Be good multiples and divisions and remember till twenty for the accurate and an efficient solution. Always remember that the common factors from the numerator and the denominator cancels each other.
Ratio is the comparison between two numbers without any units.
Whereas, when two ratios are set equal to each other are called the proportion.
Four numbers a, b, c, and d are said to be in the proportion. If $ a:b = c:d $ whereas, four numbers are said to be in continued proportion if the terms \[\] $ a:b = b:c = c:d $