Question

If \(7x : 63 = 1 : 9\), then \(x\) is

• A. 1
• B. 2
• C. -1
• D. 3

Hint:

In proportions, use cross multiplication to find the unknown variable.

Answer 1

The Correct Option is D

From the given proportion: \[\n\frac{7x}{63} = \frac{1}{9}\n\] Cross-multiplication yields: \[\n7x \times 9 = 63 \quad \Rightarrow \quad 63x = 63 \quad \Rightarrow \quad x = 3\n\] Therefore, the solution is \(x = 3\).