In an exam, A gets 25% more marks than B, B gets 10% less marks than C and C gets 25% more marks than D. If D gets 320 marks out of 500 then A's marks are?

450

25% = \(\frac{1}{4}\), 25% more = \(\frac{5}{4}\)

10% = \(\frac{1}{10}\),  10% less = \(\frac{9}{10}\)

D's marks = 320

C's marks = D's marks × \(\frac{5}{4}\) = 320 × \(\frac{5}{4}\)

B's marks = C's marks × \(\frac{9}{10}\) = 320 × \(\frac{5}{4}\) × \(\frac{9}{10}\)

A's marks = B's marks × \(\frac{5}{4}\) = 320 × \(\frac{5}{4}\) × \(\frac{9}{10}\) × \(\frac{5}{4}\) = 450