If the students of a class can be grouped exactly into 6 or 8 or 10, then the minimum number of students in the class must be. 

A person invested some amount at the rate of 12 % simple interest and a certain amount at the rate of 10 % simple interest for 1 year. He received yearly interest of Rs. ₹ 130, but if he had interchanged the amount invested, he would have received 4 more as interest. How much did he invest at 12 % simple interest? 

If  $$  \left( x^2+{1\over x^2} \right)- \left( x - {1\over 4} \right)- 7 =0 $$ then two value of x are :

Direction: The following graph shows the number of boys and girls in Class V, Class VI, Class VII and Class VIII. Study the graph and answer the question.

What is the average number of girls in all the classes?

Direction: In the following questions two equations numbered I and II are given. You have to solve both the equations and give answer.
(A) x>y
(B) x≥y
(C) x˂y
(D) x≤y
(E) x=y or the relations ship cannot be established

I. 2x+ 3y
II. 4x + 2y=16 

A man gain 15% by selling a calculator for a certain price. If he sells it at the triple price, then what will be the profit percentage?

If $$ {3^{a+3}×4^{a+6}×25^{a+1}\over{27}^{a-1}×8^{a-2}×125^{a+4}}={4\over15^{26}}$$ then the value of $$ {\sqrt{a+9}}$$.

The average weight of 8 people is increased by 2 kg when a new person comes in place of the person who weighs 50 kg. What is the weight of the newcomer?