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1. A circle wheel 28 inches in diameter rotates the same number of inches per second as a circular wheel 35 inches in diameter. If the smaller wheel makes x revolutions per second, how many revolutions per minute does the larger wheel make in terms of x?
- A. 12x
- B. 12x
- C. 12x
- D. 12x
Answer: Option B
Explanation:
For smaller wheel,
Circumference = 2×π×28/2 = 28π
Revolve in 1 second = x times
Revolve in 60 seconds = 60x times
So, distance = 28π×60x
For larger wheel,
Circumference = 2×π×35/2 = 35π
Let,
Revolve per minute = n
So, distance = 35πn
Now,
28π×60x = 35πn
Or, n = (28π × 60x)/35π
Or, n = 48x
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