Probability

A car manufacturing factory has two plants \(X\) and \(Y\). Plant \(X\) manufactures \(70 \%\) of cars and plant \(Y\) manufactures \(30 \%\) of cars. \(80 \%\) of cars at plant \(X\) and \(90 %\) of cars at plant \(Y\) are rated as standard quality. A car is chosen at random and is found to be standard quality. The probability that it has come from plant \(X\) is :