plz solve these sums

1) Three wheels make 36, 24, 60 rev/min. Each has a black mark on it. It is aligned at the start of the qn.When does it align again for the first time?
14 20 22 5 sec

2) In a race from pt. X to pt Y and back, Jack averages 0 miles/hr to pt Y and 10 miles/hr back to pr X. Sandy averages 20 miles/hr in both directions. If Jack and Sandy start race at same tIme, who’ll finish 1st
Jack Sandy they tie Impossible to tell

3) Asish was given rs 158 in denominations of Rs.1 each.He distributes these in different bags,such that the sum of money of denomination between 1 and 158 can given in bags.The min no of such bags required?

4) Boat goes downstream from P to Q in 2hrs,upstream in6hrs and if speed of stream was 1/2 of boat in still water.Find distance PQ? 6 / 4 /10 /NONE.