Mathematics

P varies inversely as the square of W. When W = 4, P = 9….

P varies inversely as the square of W. When W = 4, P = 9. Find the value of P when W = 9
  • A.
    729/16
  • B.
    6
  • C.
    4
  • D.
    16/9
  • E.
    4/3
Correct Answer: Option D
Explanation

P α 1/w2; P = K/W2
9 = K/42; 9 = K/16
K = 9 x 16 = 144
P = K/W2; when w = 9
P = 144/92 = 144/81 = 16/9