A box contains red pens and blue pens in the ratio 4:3. When we remove a red pen and two blue pens, the ratio becomes 3:2. How many red pens are now in the box?
Red / Blue = 4 / 3 (Red -1) / (Blue - 2) = 3 / 2 Use substitution to get: Red pens = 16 Blue pens = 12 16 - 1 = 15 Red pens in the box now.
