David is making rice for his guests based on a recipe that requires rice, water, and spice, where the rice-to-spice ratio is 4:1. He currently has 20 grams of the spice, but he is all out of rice. He wants to make 2 servings, where each serving has 20 grams of spice. He, therefore, goes to the store and spends $3.20 on rice. What is the price of rice per gram?

$0.02

Step-by-step explanation:

The rice-to-spice ratio is 4:1.

Each serving has 20 grams of spice

This means:

4/1 = x/20

Cross Multiply

x = 4 × 20

x = 80

Each servings = 80 grams of rice and 20 grams of spice

We are told that:

He wants to make 2 servings, where each serving has 20 grams of spice. He, therefore, goes to the store and spends $3.20 on rice.

2 servings= 2 × 80 grams of rice

= 160 grams

He goes to the store and spends $3.20 on rice.

Hence,

160 grams = $3.20

1 gram = x

Cross Multiply

160 × x = 3.20

x = 3.20/160

x = $0.02

The price of rice per gram is $0.02

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