A full turn equals four quarter turns or two half turns. Both (b) and (c) are correct. For example, the minute hand of a clock completes one full turn after 60 minutes, which can also be seen as four quarter turns.
class 5 Maths-Mela Mathematics Textbook Chapter 3 Angles as Turns question answer
CBSE Class 5 Maths-Mela Chapter 3 Angles as Turns solutions
A full turn means completing a whole circle. It can be divided in two ways: into four quarter turns or into two half turns. This shows that both (b) and (c) are correct. For example, the minute hand of a clock takes one hour to complete a full turn. In that one hour, it makes four quarter turns of 15 minutes each or two half turns of 30 minutes each.
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