How many students passed in first class?

Statements:

1. 85% of the students who appeared in examination have passed either in first class or in second class or in pass class.

11.750 students have passed in second class.

111.The number of students who passed in pass class is 28% of those passed in second class. 

What is the rate of interest per annum?

Statements:

1.The difference between the compound interest and simple interest earned in two years on the amount invested is Rs I00.

11. The amount becomes Rs I9,500 in three years on simple interest.

111. Thc simple interest accrued in two years on the same amount at the same rate of interest is Rs3.000.

The age of the father is 30 years more than the son's age. Ten years hence, the father's age will become three times the son's age that time. What is the son's present age in years?

(15.01)²x √730 =?

561÷35.05 x 19.99 =? 

 25.05 x 123.95 + 388.999 x 15.001= ?