In one pan you have 8 balls: 8n In the other pan you have the rest of balls (14 - 8 = 6) along with a <span>weight of 20 grams = 6n + 20 So the pans are balanced: 8n = 6n + 20
Now, just solve the equation: 8n - 6n = 20 2n = 20 n = 20/2 n = 10 So, you know that a ball weights 10 grams.</span>