Question

Assertion: 10 decades make a century.
Reason: 1 century is equal to 100 years and 1 decade is equal to 10 years.
A) Both assertion and reason are correct and reason is the correct explanation of assertion
B) Both assertion and reason are correct and reason is not the correct explanation of assertion
C) Assertion is correct but reason is incorrect
D) Both assertion and reason are incorrect

Answer 1

Decades and centuries are both units of time. They are multiples of years and are used to measure long periods of time.

Complete step by step answer
Decades is a period of time which is equivalent to 10 years. A decade can describe any ten-year period in time in a person’s life or in specific groupings of calendar years.
Similarly, a century is a period of 100 years. A century can also include a period of 100 years. Usually, a century is counted from the beginning of a year that is a multiple of 100. So, the 21st century starts in 2000 and ends in 2099. This is done by convention.
Decades and centuries are both units of time but they have much larger magnitudes than the SI unit of time which is seconds. So, decades and centuries, as mentioned in the hint, are multiples of years and used to measure time over long spans.
As 1 decade is 10 years and 1 decade is equal to 10 years, 10 decades will make a century. Hence the assertion and reason are correct and reason is the correct explanation of the reason.
Hence option (A) is correct.

Note
Decades and centuries are conventionally and widely used to describe long periods of time both scientifically and informally. This convention is more popular in the western calendar. Other calendars can similarly use a time period of 60 years and 52 years instead of a century. So, we should be aware of such units of time.