7 litres mixture of milk and water contains 30% water. 3.5 litres of milk is added to this mixture. What is the percentage of water in the new mixture?
A body is initially moving with a velocity of 10 m/s. It undergoes an acceleration of 2 m/s2 for 5 seconds. Find the displacement (in m) of this body in these 5 seconds.
The sum of the present ages of a father and his son is 126 years. 8 years ago their respective ages were in the ratio of 7 : 4. After 7 years what will be the ratio of ages of father and son?