Question

answer the questions below. be sure to mark all answers that apply.

	678	761	146	none of these
(b) which numbers are divisible by 3?

Explanation:

Step1: Recall divisibility rules

A number is divisible by 9 if the sum of its digits is divisible by 9, and divisible by 3 if the sum of its digits is divisible by 3.

Step2: Calculate sum of digits for 678

$6 + 7+8=21$. Since $21\div3 = 7$ and $21\div9=2\cdots\cdots3$, 678 is divisible by 3 but not by 9.

Step3: Calculate sum of digits for 761

$7 + 6+1 = 14$. Since $14\div3=4\cdots\cdots2$ and $14\div9 = 1\cdots\cdots5$, 761 is not divisible by 3 or 9.

Step4: Calculate sum of digits for 146

$1+4 + 6=11$. Since $11\div3 = 3\cdots\cdots2$ and $11\div9=1\cdots\cdots2$, 146 is not divisible by 3 or 9.

Answer:

(a) None of these
(b) 678