The age of a father is twice that of the sum of the ages of his two sons. 20 years later, the age of the father will become the sum of the ages of his two sons. The present age of the father is
A monkey climbs a 12 meters high slippery pillar. In his first minute, he climbs 2 meters and in the next minute, he slips one meter down. In this way, how much time will he take to reach the top of the pillar?
A rectangular field is 112 mt. long and 62 mt. broad. A cubical tank of edge 6 mt. is dug at each of the four corners of the field and the soil so removed is evenly spread on the remaining field. Find the rise in the level of the field.
3 men or 7 women finish a work in 32 days. 7 men and 5 women together will finish the twice of this work in
The mean of first twenty positive even numbers is
