A rises from his house at 12 noon towards B’s house at a speed of 8 km/hour. After 1 hour, B rides from his house towards A’s at a speed of 7 km/hour. If the distance between the two houses is 68 km, the time when they meet is

Direction: The following table shows the number of students of 7 colleges A, B, C, D, E, F, G participating in extra-curricular activities :

The college in which minimum number of students participate in extracurricular activities is ? 

The radii of three concentric circles are in the ratio of 4 : 5 : 7. What is the ratio of the area between the two inner circles to that between the two outer circles?

Present age of Ram and Shyam are in the ratio of 4: 5 respectively. Five year hence the ratio of their age becomes 5:6 respectively. What is Ram’s present age?

The average weight of five persons sitting in a boat is 38 kg. The average weight of the boat and the persons sitting in the boat is 52kg. What is the weight of the boat?

Find the equation of the line that passing through the point (7, -5 ) and is perpendicular to  the line (4x+5y=1).

If sin²a = cos³a then the value of cot⁶ a – cot²a? 

A certain sum of money lent out at simple interest amounts to Rs. 2400 in 4 years and Rs. 3000 in 6 years. Find the rate of interest per annum?