Question

Alice added 3 to three fourths of a number she got 21 What is the number​

Answer 1

Let the unknown number be n

Then,

$\to \bf{}3 + \frac{3n}{4} = 21 \\ \\ \to \tt \frac{12 + 3n}{4} = 21 \\ \\ \to \tt \frac{12 + 3n}{ \cancel4} \times \cancel4 = 21 \times 4 \\ \\ \to \tt12 + 3n = 84 \\ \to \tt3n = 84 - 12 \\ \to \tt3n = 72 \\ \\ \to \tt \frac{\cancel3n}{\cancel3} = \frac{72}{3} \\ \\\to \tt{}n = \red{ \sf24}$

Thus,

• 24 is the required number whose 3/4th when added to 3, the obtained result is 21.