The average of 21 consecutive natural numbers is 53. What is the value of the smallest of these 21 numbers?

The ratio of efficiency of Arun is to Chitra is 5:3. The ratio of number of days taken by Bala is to Chitra is 2:3. Arun takes 6 days less than Chitra, when Arun and Chitra complete the work individually. Bala and Chitra started the work and left after 2 days. The number of days taken by Arun to finish the remaining work is?

The average age of a cricket team of 11 players is the same as it was 3 years back because 3 of the players whose current average age of 33 years are replaced by 3 youngsters. The average age of the new comers is: 

The equidistant point from the vertices of a triangle is called its: 

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. x² + 13x = - 42
II. y² + 16y + 63 = 0 

A farmer has 945 cows and 2475 sheep. He farms them into flocks, keeping cows and sheep separate and having the same number of animals in each flock. If these flocks are as large as possible, then the maximum number of animals in each flock and total number of flocks required for the purpose are respectively