1 Ounce of Butter = B
Bowl of Curry = C
1 Hour = H
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A restaurant requires 4 + 1/2 ounces of butter for every bowl of curry it makes...
C = 9/2 * B
In an hour, an average of 2 + 1/2 bowls of curry is served...
H = 5/2 * C
... Which means that: H = 5/2 * 9/2 * B
... So: H = 45/4 * B
The question was: How many ounces of butter are required in 1 + 1/2 hours?
Here is the answer:
3/2 * H = 3/2 * 45/4 * B
3/2 * H = 135/8 * B
In words, 16 + 7/8 ounces of butter would be required over a period of 1 + 1/2 hours.