In a school, the bell is rung once after each half an hour. The school starts at 8:00 a.m. and closes at 1: 30 p.m. The bell is rung 3 times continuously, at the time of beginning, at the time of lunch break at 10:00 and 10:30 a.m. and at the end. How many times is the bell rung every day? 

Which interchange of signs will make the following equation correct?
35 + 7 * 5 ÷ 5 - 6 = 24

Mouni is 2 years elder than Sanjay. If the age of Sanjay 10 years ago was 13 years, then Mouni's present age is

If 5=10, 6=18, 7=28 then 8=?

which of the following meanings of the arithmetical signs will yield the value ' zero ' for the expression given below?
200x100 + 300 x 200 10÷2 + 40

If ‘+’ stands for division, ÷ stands for multiplication, multiplication stands for addition; then which one of the following equation is correct?

The weights of 4 boxes are 30, 40, 50 and 80 kilograms. Which of the following cannot be the total weight, in kilograms, of any combination of these boxes and in a combination a box can be used only once?

A man takes 6 km distance to go around the rectangular area. If the area of the rectangle is 2 sq. km. find the difference between length and breadth.