A man has eaten 100 grapes in 5 days. He eats 6 more grapes every day in comparison to the previous day. How many grapes did he eat on the first day?

A student multiplies a number with 7.2 instead of 0.72. If due to this answer is 2592 more than the right answer, then what was the original number? 

If the length and breadth of a rectangle are increased by 8 % and 12 % respectively, then by what percent does the area of that rectangle increase? 

There are four numbers in a set. The mean of the three smallest numbers is 9, whereas the mean of the three largest ones is 11. What is the range of the data set? 

Find compound interest on Rs. 50000 at 12 % per annum for 6 months, compounded quarterly. 

Subjects, there were 9 boys and some girls. In a test, the mean score obtained by the boys was 13 while that obtained by the girls was 15. If the overall average was 14.28, what was the total number of students in the class? 

The digit in the unit's place of the number represented by (7⁹⁵ - 3⁵⁸) is: 

The lengths of one side of a rhombus and one of the two diagonals are 6 cm each. Find the area of the rhombus (in cm²).