Question

1. the school store sold 9 packs of yellow pencils, and 8 packs of red pencils. there were 12 pencils in each pack. how many pencils did they sell? answer 2. circle the numbers below that are prime: do not just guess! make the effort and use your divisibility rules. 23, 18, 9, 2, 55, 97 80, 71, 37, 1

Explanation:

Step1: Calculate total packs

Find total packs of pencils: \(9 + 8=17\) packs.

Step2: Calculate total pencils

Since each pack has 12 pencils, total pencils \(=17\times12\).
Using distributive property: \((10 + 7)\times12=10\times12+7\times12 = 120+84=204\).

A prime number has only two distinct positive divisors: 1 and itself.

• \(23\): Divisors are 1 and 23 (prime).
• \(18\): Divisors include 1, 2, 3, 6, 9, 18 (not prime).
• \(9\): Divisors 1, 3, 9 (not prime).
• \(2\): Divisors 1 and 2 (prime).
• \(55\): Divisors 1, 5, 11, 55 (not prime).
• \(97\): Divisors 1 and 97 (prime).
• \(80\): Divisors include multiple numbers (not prime).
• \(71\): Divisors 1 and 71 (prime).
• \(37\): Divisors 1 and 37 (prime).
• \(1\): By definition, not a prime number (has only one positive divisor).

Answer:

204