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Directions (Q91–95): Food X contains 6 units of vitamin D per gram and 7 units of vitamin E per gram and costs Rs 12 per gram. Food Y contains 8 units of vitamin D per gram and 12 units of vitamin E per gram and costs Rs 20 per gram. The daily minimum requirements of vitamin D and E are 100 units and 120 units respectively. Let x be the quantity (in grams) of food X and y the quantity (in grams) of food Y.

What are the quantities (in grams) of food X and Y respectively when the cost of food is minimum?

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Correct answer: B. 15 and 5/4

Explanation

Corner points: (0, 12.5) gives cost 250; the intersection of 6x + 8y = 100 and 7x + 12y = 120 is (15, 1.25), cost 180 + 25 = 205; (120/7, 0) gives ≈ 205.7. The minimum is at x = 15, y = 5/4.

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