Use proportional relationships to solve this mixture problem. Wendell is making a fruit salad consisting of melon and strawberry. Melon costs $0.45 per pound and strawberries cost $1.65 per pound. He wants his fruit salad to contain 4 times as much melon as strawberries. If Wendell has $10.50, how many whole pounds of melon and how many whole pounds of strawberries should he buy for his fruit salad?
Let's assume that Wendell buys x pounds of strawberries for his fruit salad.
According to the given information, Wendell wants his fruit salad to contain 4 times as much melon as strawberries. So, the weight of melon in the fruit salad is 4x pounds.
The total weight of the fruit salad is x + 4x = 5x pounds.
Since melon costs $0.45 per pound, the cost of melon in the fruit salad is 0.45 * 4x = $1.8x.
Similarly, the cost of strawberries in the fruit salad is 1.65 * x = $1.65x.
The total cost of the fruit salad is 1.8x + 1.65x = 3.45x.
Since Wendell has $10.50, we can set up the following equation to solve for x:
3.45x = 10.50.
Dividing both sides of the equation by 3.45 gives x = 3.
Therefore, Wendell should buy 3 pounds of strawberries and 4 * 3 = <<3*4=12>>12 pounds of melon for his fruit salad. Answer: \boxed{3, 12}.