A boy added all natural numbers from 1 to 10, however, he added one number twice due to which the sum becomes 58. What is the number which he added twice? 

If the circumference of a circle is 4.4 m, then the area of the circle (in m²) is :

In the given figure AB, BC and CA is a tangent of a circle if BC=6.3 cm and MC=2.7 cm then the Value of BL is                                                                

A number increased by   $$22{1 \over 2}\%$$ gives 98 as result. The number is: 

Fill in the blanks:
Sin A = ____ × (Cos A) 

One fill pipe A takes 3 minutes more to fill the cistern than two fill pipes A and B opened together to fill it. Second fill pipe B takes $$ {21{1\over 3}}$$ minutes more to fill cistern than two fill pipes A and B opened together to fill it. When will the cistern be full if both pipes are opened simultaneously?

On selling an article for Rs 162 there is a loss of 10%.At what price it should be sell in order to gain a profit of 10%?

In how many different ways can the letters of the word 'NATIONAL' be arranged?