Question

If 18:30 :: 30 : x, then find the value of x.

• A. 50
• B. 40
• C. 35
• D. 45

Answer 1

Answer:

A. 50

to find the 4th proportion

$18:30 :: 30 : x$

$=\frac{30\times 30}{18}$

$=\frac{900}{18}$

$=\frac{100}{2}=50$