Question

a popular brand of pen is available in 10 colors and 3 writing tips. how many different choices of pens do you have with this brand? there are \boxed{} different choices of pens with this brand.

Explanation:

Step1: Apply multiplication principle

Each color pairs with each tip. So multiply color count by tip count.

Step2: Calculate total choices

$10 \times 3 = 30$

Answer:

30