Direction : The table given below represents number of bikes of five different brands sold from 2001- 2005, with the help of data given in the table, answer the following questions.

If sales of Suzuki in the year 2006 is increased by 5% and sales of Yamaha decreased by 5%, then what is the difference of averages of sales of Suzuki in year 2001 and 2006 and average sales of Yamaha in 2002 and 2006?

If $${b\over a}=0.7$$ find the value of $${a-b\over a+b}={11\over34}.$$

The price of a variety of a commodity is ₹7/kg and that of another is ₹12/kg. Find the ratio in which two varieties should be mixed so that the price of the mixture is ₹10/kg.

If $$ {a^4+1}={{a^2}\over{b^2}}{(4b^2-b^4-1)}$$,then what is the value of $${a^4+b^4}$$?

Evaluate the following.

sin 25° sin 65° – cos 25° cos 65°.

The radius of a cone is 20 cm and height is 21 cm, the total surface area of the cone is in square cm:

Read the following graph carefully and answer the related questions-

Total number of students (in thousands) participating in comitative exam in various cities.

What is the percentage of students appearing in competitive exam from city E to total number of students appearing for competitive exam from all the states? 

If $$ {x^{4}+x^{2}y^{2}+y^{4}={21\over256}}$$ and $$ {x^{2}+xy+y^{2}={3\over16}}$$ then $$ {2(x^{2}+y^{2})}=?$$