JAMB 1999 · UME · Q7

Simplify $\sqrt{\dfrac{0.0023 \times 750}{0.00345 \times 1.25}}$ .

Worked solution (try it first)

Pair the numbers: $\dfrac{0.0023}{0.00345} = \dfrac{2300}{3450}$ , which is $\frac23$ .
And $\dfrac{750}{1.25} = 600$ .
So the fraction is $\frac23 \times 600 = 400$ , and $\sqrt{400} = 20$ , option B.