The average of three numbers is 40. First number is 4/3 of the third number. If third number is 20 less than second number, then what is the value of second number?
A man starts walking at 6.30 a.m. and wants to cover a distance of 30km. His initial speed is 6 kmph and after covering three-fifth distance, he reduces his speed by 2 kmph. At what time will he complete his walk?