A toothed wheel of diameter 50 cm is attached to a smaller wheel of diameter 30 cm. How many revolutions will the smaller wheel make when the larger one makes 15 revolutions?
Choose the correct choice from the following options:
A) 18 B) 20 C) 22 D) 25 E) 27
Solution   Distance covered by smaller wheel in 1 revolution = (2Π x 15) cm   = (30 Π) cm.   Distance covered by larger wheel in 1 revolution = (2Π x 25) cm   = (50 Π) cm.   Let k x 30 Π = 15 x 50 Π.   Then, k = [15 x 50 Π / 30 Π] = 25.   ∴ Required number of revolutions = 25.   Answer 25
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A toothed wheel of diameter 50 cm is attached to a smaller wheel of diameter 30 cm. How many revolutions will the smaller wheel make when the larger one makes 15 revolutions?