Answer:
each pencil almost costs 83 cents which is the value of p
Explanation:
Here most important data that the amount which Kate had before the purchase of pencils is missing.
For our convenience i am assuming Kate had $10 before the purchase of pencil.
Since, after purchase the left with Kate = $4.20
Therefore, amount spend on purchase of pencils = $10-$4.20 = $5.80
In $5.80 Kate purchased 7 pencils
Therefore cost of each pencil p = 5.80/7 = $0.8285 ≅ $0.83
Therefore each pencil almost costs 83 cents which is the value of p