Tom Jerry and Bill start from point A at the same time in their cars to go to B Tom reaches point B ...........

Explanation:

Let the distance between A and B be ‘x’ miles.
Let their speeds be T, J and B in miles/hour
When Tom meets Jerry:
Distance travelled by Tom = x + 9
Distance travelled by Jerry = x – 9
Time taken will be the same => x + 9 /T = x + 9 /J
or T/J = x + 9 /x - 9 ...........(i)
When Jerry meets Bill:
Distance travelled by Jerry = x + 7
Distance travelled by Bill = x – 7
Time taken will be the same => x + 7 /J = x - 7 /B

5(x - 9)(x - 7) = 3 (x + 9)(x + 7)
5x² – 80x + 315 = 3x² + 48x + 189
2x² – 128x + 126 = 0
x² – 64x + 63 = 0
x = 63 or x = 1
Therefore, X has to be 63 miles