Solve the following problems:

Reena took loan of Tk 1200 at simple interest rate for as many years as the rate of interest. If she paid Tk.432 as interest at the end of the loan period, what is the rate of interest?

Mathematics

A brother and a sister share out their collection of 5,000 stamps in the ratio of 5 : 3. The brother then shares his stamps with two friends in the ratio of 3 : 1 : 1 keeping most for himself. How many stamps does each of his friends receive?

Mathematics

If the length of the two sides of a trapezoid are 4cm and 7cm and height of the trapezoid is 7cm, calculate the area of the trapezoid.

Mathematics

40% of the students of a class failed in statistics and 35% of students failed in computer studies. If the class size is 200 and 70 students failed in neither of the subjects, then how many students failed in both the subjects?

Mathematics

The ratio between the length and the breadth of a rectangular park is 3 : 2. If a man cycling along the boundary of the park at the speed of 12km/hour completes one round in 8 minutes, then what is the area of the park in square meters?

Mathematics

$if \frac{x^2-7x+12}{x^2+4}=3$, calculate the value of x.