6) The simple interest and the true discount on a certain sum for a given time and at a given rate are Rs. 85 and Rs. 80 respectively. The sum is:

7) The angle of elevation of the sum, when the length of the shadow of a tree 3 times the height of the tree, is

8) For which of the following disciplines is Nobel Prize awarded?

9) Out of 7 consonants and 4 vowels, how many words of 3 consonants and 2 vowels can be formed?

10) The ratio between the perimeter and the breadth of rectangle is 5:1. If the area of the rectangle is 216 sq. cm, what is the length of the rectangle?