If \( p \) pens weigh 120 grams, how much will 70 pens weigh?

To find the weight of 70 pens, we first need to determine the weight of one pen. Since \( p \) pens weigh 120 grams, the weight of one pen can be calculated as \( \frac{120}{p} \) grams. Now, we can find the weight of 70 pens: \[ \text{Weight of 70 pens} = 70 \times \frac{120}{p} = \frac{8400}{p} \text{ grams}. \] Therefore, the weight of 70 pens depends on the value of \( p \). For example, if \( p = 10 \), then 70 pens will weigh \( \frac{8400}{10} = 840 \) grams. This means that to get a precise answer, you need to know how many pens \( p \) represents.