Question

What fraction of a clockwise revolution does the hour hand of a clock turn through, when it goesfrom (a) 3 to9 (b) 4 to 7 (c) 7 to10 (d) 12 to9 (e) 1 to 10 (f) 6 to3

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Answer 1

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We may observe that in 1 complete clockwise revolution, the hour hand will rotate by 360°.

(a) When the hour hand goes from 3 to 9 clockwise, it will rotate by 2 right angles or 180° or two right angles .

(b) When the hour hand goes from 4 to 7 clockwise, it will rotate by 1 right angles or 90° or one right angle .

(c) When the hour hand goes from 7 to 10 clockwise, it will rotate by 1 right angles or 90° or one right angle .

(d) When the hour hand goes from 12 to 9 clockwise, it will rotate by 3 right angles or 270° or three right angles.

(e) When the hour hand goes from 1 to 10 clockwise, it will rotate by 3 right angles or 270° or three right angles.

(f) When the hour hand goes from 6 to 3 clockwise, it will rotate by 3 right angles or 270° or three right angles.

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Answer 2

Answer:

we know that 12 hours make 1 full revolution

1 hour = 1/12 revolution

a) 6/12=1/2 revolution   (3 to 9 is 6 hours)

b) 3/12=1/4 revolution   (4 to 7 is 3 hours)

c)3/12= 1/4 revolution

d) 9/12=3/4 revolution   (9 hours)

e) 9/12=3/4 revolution    (9 hours)

f) 9/12= 3/4 revolution

hope it helps...