Since the dealer mixes

a=1 pounds of nuts worth b=30 cents per pound

and c=2 pounds of nuts at d=15 cents per pound,

he would be selling one pound of this mixture at \(\frac{1*30 + 2*15}{1 + 2} = \frac{60}{3} = 20\) cents

For the dealer to make a profit of 10 cents per pound, he would have to sell the mixture at \(30\) cents.

Evaluating answer options,

(A) (ab + cd)/(a + c) + 10 = 1*30 + 2*15/(1 + 2) + 10 = 30 cents.

Therefore,

Option A((ab + cd)/(a + c) + 10) is the price at which the dealer should sell a pound of the mixture.

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