Quantitative Aptitude - Arithmetic Ability Questions

a, b and c are 3 values, such that a + b = 5, b + c = 7.5 and c + a = 8.5. What will be the average of these values?

Abhishek marks the price of his laptop 60% above the cost price. If he gives a discount of 30% on the marked price, then what is the profit percentage?

If Rajan purchase 21 pens for Rs 20 and sell all the pens at the rate of 20 pens for Rs 21, then what will be the profit percentage?

Ages of Lalu and Balu are in the ratio of 1 : 2. After 7 years their ages ratio changes to 3 : 5. The elder person age is

7 litres mixture of milk and water contains 30% water. 3.5 litres of milk is added to this mixture. What is the percentage of water in the new mixture?

1/3 part of a certain journey is covered with the speed of 25 km/hr, 1/2 part of the journey is covered with the speed of 45 km/hr and the remaining part covered with the speed of 37.5 km/hr. What is the average speed (in km/hr) for the whole journey?

Rs. 3105 is due to be divided among K, L and M in the proportion of 2/3 : 3/4 : 1/2 respectively. How much will L get?

If x = at2 and y = 2at then