Question

What decimal of an hour is a second?
A). $.00002\overline 9 $
B). $.0002\overline 8 $
C). $.0002\overline 7 $
D). $.0002\overline 6 $

Answer 1

Hint: Before attempting this question, one should have prior knowledge about the time dimensions and units and also remember that 1 hour is equal to 60 minutes and 1 minute has 60 seconds. Using this information, it can help you to approach the solution of the problem.

Complete step-by-step solution:
According to the question, we all know that
1 hour is equal to 60 minutes and 1 minute have 60 seconds
From above calculation, we can conclude that in 1 hour we have
$ \Rightarrow $$1hour = 60\min \times 60\sec $
 Therefore, we can say that 1 second is equal to \[\dfrac{1}{{3600}}\]hour
So, \[1\sec = 0.000277777\]
Since in above result, 7 is the recurring decimal and we know that we can use the bar ($\overline n $) sign to represent the recurring decimals. A circulating(recurring) decimal is a decimal representation of variety whose digits are periodic (repeating its values at regular intervals) and therefore the infinitely repeated portion isn't zero.
Therefore \[1\sec = 0.0002\overline 7 \]
Hence, option “C” is the correct answer.

Note: In the above question there was a simple trick to approach the solution as a general rule, dividing your number of minutes by 60 will give you the same time in hours. This is because there are exactly 60 minutes in an hour. For the second divide 60 min in the number of seconds to get the accurate answer.