The driver of a vehicle traveling at a speed of 80 kmph on an up gradient requires 48m less to stop after applying the brake, than a driver traveling at same speed down the same gradient. Find out the gradient of a road in %. if the braking efficiency of upgrade and downgrade is 80 % & 60 % respectively.
[Assume f = 0.40]
Enter numerical value using the virtual keypad. Round off where necessary.