Question

1. which pair of equations has 8 as the unknown?

a. $3 \times \square = 36$
$36 \div \square = 3$
b. $\square \times 3 = 24$
$24 \div \square = 3$
c. $7 \times \square = 40$
$40 \div 7 = \square$
d. $\square \times 8 = 72$
$72 \div 8 = \square$

Explanation:

Step1: Analyze Option A

For \(3\times\square = 36\), solve \(\square=36\div3 = 12\). For \(36\div\square = 3\), \(\square = 36\div3=12\). Not 8.

Step2: Analyze Option B

For \(\square\times3 = 24\), \(\square=24\div3 = 8\). For \(24\div\square = 3\), \(\square=24\div3 = 8\). Both give 8.

Step3: Analyze Option C

For \(7\times\square = 40\), \(\square = 40\div7\approx5.71\). Not 8.

Step4: Analyze Option D

For \(\square\times8 = 72\), \(\square=72\div8 = 9\). For \(72\div8=\square\), \(\square = 9\). Not 8.

Answer:

B. \(\square \times 3 = 24\), \(24 \div \square = 3\)