Bhanu takes a total of 6 hrs 50 min in walking a distance and running back to same place where she started. She could walk both ways in 8 hrs 30 min. The time taken by her to run both ways is :
An alloy contains copper and tin in the ratio 3 : 2. If 250 gm of copper is added to this alloy then the copper in it becomes double the quantity of tin in it. What is the amount (in gm) of tin in the alloy?