Answer:
Length of the thread = 30 metres
Step-by-step explanation:
Length of the thread in one round of a reel = Circumference of the reel
C =
Since radius of the reel =
=
= 2.5 cm
Circumference of the reel = 2(π)(2.5)
= 5π
= 5×3
= 15 cm
Length of the thread wound in one round around the reel = 15 cm
Since, thread is wound 200 times round a reel, length of the thread
= 200 × 15
= 3000 cm
≈ 30 metres
Therefore, Option (B) will be the answer.