A man was 32 years of age when he had his first son. His wife was 35 years of age when his son attained the age of 7 years. The difference between the age of the father and the mother is _____
A man covers a total distance of 100 km on bicycle. For the first 2 hours, the speed was 20 km/hr and for the rest of the journey, it came down to 10 km/hr. The average speed will be
A does 1/2 as much work as B and C does1/2as much work as A and B together. If C alone can finish the work in 40 days, then together all will finish the work in