Quantitative Aptitude - Arithmetic Ability Questions

In a class, 60% of children like Mathematics, 45% like Science and 25% like both Mathematics and Science. What is the percentage of children who like at least one subject?

A student multiplied a number by 6/7 instead of 7/6. What is the percentage error in the calculation?

A box weighs 8.5 kg when full of sand and weighs 5.5 kg when it is half filled with sand . Weight of the empty box is

A sum of Rs 2000 becomes Rs 3645 in 2 years at a certain rate of compound interest. What will be the sum (in Rs) after 4 years?

The marked price of a helmet is 30% more than its cost price. If the helmet is sold for Rs 744 after a discount of Rs 36, then what will be the profit percentage?

What is the simplified value of Sec ACot A + Tan A2 ?

X and Y are the mid points of sides AB and AC of a triangle ABC. If BC+XY=12 units, then BC-­XY is

2 litre of pure alcohol is added to 6 litre, 40% alcohol solution. The percentage of water in the solution is _____ .