Select the number that will come in place of the question mark (?) in the following mathematical statement.

$${5\over 9} \ of \ {11\over 14}\ 42\% \ of \ 540=?^2 -45 $$

12 men complete a work in 18 days. Six days after they had started working, 4 men joined them. How many days will all of them take to complete the remaining work?

If Sonu is driving a car at a speed of 20m/s, then in how much time Sonu will cover a distance of 936 km?

180 m long Train A crosses Train B of 120 m in length which is running in opposite direction in $$ {60\over 11}$$ sec. If speed of train B is 20% more than that of train A, then find the time taken by both trains to cross each other, when they running in same direction?

A man walks a certain distance and rides back in 4 hours 30 minutes. he could ride both ways in 3 hours. The time required by the man to walk both ways is 

a, b, c, d, e, f, g are consecutive even numbers. j, k, l, m, n are consecutive odd numbers. The average of all the numbers is: 

The HCF of two numbers, each having three digits, is 17 and their LCM is 714. The sum of the numbers will be: