A train was moving with uniform speed.after covering a distance of 30 km , some defect developer in the engine of train and for this reason , its speed is
reduced to 4/5 of its original speed. the train reaches its destination late by 45 minutes. in case the defect had happened after covering 18 km more ,the train would have reached just 36 minutes late. find the speed of the train at the start and the total distance of the journey.