If the sum and difference of two number are 20 and 8 respectively, then the difference of their squares is: 

Direction : What value should come in the place of question mark (?) in the following questions?

80% of 10% of 340 = ?

If a 12 meter rod is cut into 25 equal pieces, what is the length of each piece?

Simplification the following equations shown below

What approximate value should come at place of the question mark(?) in the following question?

Direction : What value should come in the place of question mark (?) in the following questions?

125% of 2440 – 75% of 1856 = ?

Simplify the following equation.
$$ {(100)}^{1\over2}.{(0.001)}^{1\over3}-{(0.0016)}^{1\over4}.{3}^{0}+({5\over4})^{-1} $$