A typist uses a sheet measuring 20cm by 30cm lengthwise.If a margin of 2 cm is left on each side and a 3 cm margin on top and bottom, then percent of the page used for typing is

A 64%

B 74%

C 84%

D 94%

Correct Answer: Option A

Area of the sheet = \(\left(20\times30\right)cm^2\)

Area used for typing = \(\left[\left(20-4\right)\times\left(30-6\right)\right]cm^2\)

required % = \(\frac{384}{600}\times100\) =64%