Question

What must be added to each of 7, 16, 43 and 79 so that they are in proportion?

• A. 9
• B. 17
• C. 33
• D. 5

Answer 1

The correct option is D

5

Let x be added to each of 7, 16, 43 and 79 so that the resulting number are in proportion. i.e. (7 + x) : (16 + x) : : (43 + x) : (79 + x)
$\frac{7+x}{16+x}=\frac{43+x}{79+x}$, by solving this equation, we get
x = 5