A grocer mixes two types of coffee, one costing $8 per pound and another costing $12 per pound, to create a blend. If the blend costs $10 per pound, and there are 30 pounds of the cheaper coffee in the blend, how many pounds of the more expensive coffee are in the blend?
✓ Correct Answer: Option D
Let x be the pounds of expensive coffee. Total cost equation: 8(30) + 12x = 10(30 + x). 240 + 12x = 300 + 10x. Subtracting 10x and 240 from both sides: 2x = 60. So, x = 30 pounds.