$$4a-{4\over a}+3=0$$ then the value of :   $$ a^3-{1\over a^3}+3=?$$

In ∆ABC, ∠A=90⁰ , AD is the bisector of ∠A meeting BC at D, and DE ⊥ AC at E. if AB = 10 cm and AC = 15 cm, then the length of DE, in cm, is:

Directions: The following pie chart show proportion of population of seven villages in 2009. Stud the pie chart and answer question that follows:

The ratio of the below poverty line population of village 'T' to that of the below poverty line population of village 'Z' is 

Direction: In the given question, two equations numbered l and II are given. Solve both the equations and mark the appropriate answer.

I. 9x² – 3x – 2 = 0
II. y² – 8y + 16 = 0

Direction: Study the following line graph carefully and answer the questions given below.
 In the below line graph, the number of animals in two zoo A and B in the years – 2001, 2003, 2005 and 2007 is given.

Sum of the number of animals in zoo-B in the years 2001, 2003 and 2005 together is what per cent more/less than the sum of the number of animals in zoo-A in the years 2001 and 2007 together? 

On a rainy day, 60 cm of rain is recorded in a region. What is the volume of water collected in an open and empty rectangular water tank that measures 12 m (length) ×10 m (width) and 50 cm (depth)?

If a + b – c = 0 then the value of 2b²c² + 2c²a² + 2a²b² –a⁴ – b⁴ – c⁴

Mohan lent some amount of money at 9% simple interest and an equal amount of money at 10% simple interest each for two years. If his total interest was Rs. 760, what amount was lent in each case?