Quantitative Aptitude - Arithmetic Ability Questions

A shopkeeper marks his goods 50% more than the cost price and allows a discount of 25%. His profit or loss percentage is:

The marked price of an article is 10/7 of the cost price and the selling price of that article is 4/5 of the marked price. What is the profit percentage?

If the present ages of a father and his son are 48 years and 28.8 years old respectively, then the father can say to his son, "I was ......... of your present age when you were born".

The average age of 6 members of a family is 20 years. If the age of the servant is included, then the average age increase by 25%. What is the age (in years) of the servant?

In what ratio should coffee powder costing Rs 2500/kg be mixed with coffee powder costing Rs 1500/kg so that the cost of the mixture is Rs 2250/kg?

A can paint a house in 45 days and B can do it in 15 days. Along with C, they did the job in 5 days only. Then, C alone can do the job in how many days?

Working together A and B can do a job in 40 days, B and C in 36 days and all three together in 24 days. In how many days can B alone do the job?

A fraction becomes 6/5 when 5 is added to its numerator and becomes 1/2 when 4 is added to its denominator. What will be the value of the fraction?