If u : v= 4 : 7 ,  v : w = 9 : 7 and u=72 then find the value of w.

A sum of money becomes double in 3 years at compound interest compounded annually at the same rate. In how many years will it become four times of itself? 

A sum of money at double the rate of simple interest doubles itself in 10 years. In how much time will that amount be triple of itself?

The following penalty diagram shows the 4 year exam results of the students of 10th standard. Study the diagram and answer the following questions.

State the percentage increase in the first division in the year 2003 as compared to the year 2002:

117.5, 117, 119, 111, 143, ?

A person completes a journey of 30 km at a speed of 6 km / h and a journey of the remaining 40 km at a speed of 8 km / h. What is his average speed of travel for the entire journey?

Find the maximum number of students among them 1001 pens and 910 pencils can be distributed in such a way that each student gets the same number of pens and same number of pencils.

Find the equation of the line that passing through the point (7, -5 ) and is perpendicular to  the line (4x+5y=1).