A motorist travels to a place 150 m away at an average speed for 50 km and returns at 30 km per hour. What is his average speed for the whole journey in km per hour ?

The average of Selim's marks in 7 subjects is 75. His average in six subjects excluding Science is 72. How man...

What is the value of x if 4/x +3/5 = 10/x ?

If 3a+4b = 10 and 5a+3b=30, what is the average (arithmetic mean) of a and b ?

The number of marbles in Amin's collection is 80% of the number in Rahim's collection. If Rahim has 80 more ma...

A water reservoir is 1/5 th full and requires 20 liters more to make it 3/5 th full. What is the capacity of t...

A third of Karim's marks in Mathematics exceeds a half of his marks in Social Studies by 30, if Karim got 240...