4. Solve the following:
(a) Some part of journey of 555km is completed by a car with speed 60km/h, then the speed is increased by 15km/h and journey is completed. If it takes 8hrs to reach, find the time taken and distance covered by 60km/h speed
(b) Monthly income of two persons is in ratio 4:3, each of them saves rs600 per month. If the ratio of their expenses is 3:2 then find the monthly income of each person.​