pamela vendio 3 chocolates de 14 g cada uno y obtuvo una ganancia de $21. Si quiere ganar $400 mediante la venta de 20 chocolates ¿cuantos gramos debe de pesar cada chocolate?

Correct option: first one -> 40

Step-by-step explanation:

To solve this problem, we can use a compound rule of three.

The quantity of chocolate and the weight of each chocolate are inversely proportional: to achieve the same earning, if we have more chocolate, we need less grams per chocolate.

Then, the rate of change in quantity multiplied by the rate of change in the grams will be equal to the rate of change in the final earning.

So we have that:

(3/20) * (14/X) = 21/400

42 / 20X = 21 / 400

1 / 10X = 1 / 400

10X = 400

X = 40 grams

Correct option: first one

x = 12

y = 15

step-by-step explanation: