In a computer game, a builder can build a wall in ten hours while a destroyer can demolish such a wall completely in fourteen hours. Both, the builder and the destroyer were initially set to work together on level ground. But after 7 hours the destroyer was taken out. What was the total time (in hrs) taken to build the wall ?
The simplified value of is A circle is inscribed in a triangle ABC.It touches sides AB, BC and AC at points P, Q and R respectively. If BP = 9 cm, CQ = 10 cm and AR = 11 cm, then the perimeter (in cm)of the triangle ABC is: