What should be the maximum value of q in the following equation?
5P9 - 7Q2 + 9R6 = 823

A. 5

B. 6

C. 7

D. 9

E. None of these

Answer: Option C

Solution(By Examveda Team)

⇒ 5P9 - 7Q2 + 9R6 = 823
⇒ (500 + 10P + 9) - (700 + 10Q + 2) + (900 + 10R + 6) = 823
⇒ (500 + 900 - 700) + 10 (P + R - Q) + (9 + 6 - 2) = 823
⇒ 700 + 10 (P + R - Q) = 810
⇒ 700 + 10 (P + R - Q) = 700 + 110
⇒ 10 (P + R - Q) = 110
⇒ P + R - Q = 11
⇒ Q = (P + R - 11)
To get maximum value of Q we take P = 9 and R = 9
This gives Q = (9 + 9 - 11) = 7
Hence, the maximum value of Q is 7