How many two-digit numbers are divisible by 3 but not by 7?

$$3\sqrt{ {72.9\over0.4096}}$$ is equal to : 

Study the following graph and answer the question that follow.
What is the different between the numbered of candidates appeared from institutes A, C, D and F together and candidates passed from institute-B, E and G together?

If (a + b):(b + c):(c + a) = 7:6:5 and a + b + c = 27, then what will be the value of 1/a: 1/b :1/c?

A goat is tied with a 10.5 m-long rope to one corner of a plot which is in the shape of an equilateral triangle each side of which is 16 m long. Find the area that the goat can graze on.

If $$ {4x^2}={25}^2-{15}^2 $$, then find the value of x.

Directions: The bar graph given below shows the spending of family income on various items and savings during 1993. Observe the graph and answer the following questions:

The percent of income spent on clothing exceeds that on savings by : 

If cos θ + sin θ =m, sec θ + cosec θ =n, what is m/n?