Pihu and Aayu are running on a circular track of diameter 28m. Speed of Pihu is 48 m/s and that of Aayu is 40 m/s. They start from the same point at the same time in the same direction. When will they meet again for the first time?
X and Y are two alloys which are prepared by mixing zinc and aluminium in the ratio of 1 : 4 and 11 : 8 respectively. If equal quantities of alloys are melted to form a third alloy Z then what is the ratio of zinc and aluminium in alloy Z?