Quantitative Aptitude - Arithmetic Ability Questions

A man is 3 years older than his wife and four times as old as his son. If the son becomes 15 years old after 3 years. Then what is the present age of the wife?

A shopkeeper increases the price of an object by 40% and then sells it at 25% discount on the marked price. If the selling price of such an object be Rs. 2100, its cost price for the shopkeeper was ?

Seven years ago, the age of Sahil was equal to the present age of Nihal. Sum of Sahil's age 5 year ago and Nihal's age 6 years later is 58 years. If Ruchi is 4 years elder to Sahil, then what will be Ruchi's age (in years) after 10 years?

The average of 9 observations was found to be 35. Later on, it was detected that an observation 81 was misread as 18. The correct average of the observations is

(45.004% of 1439.97 –15.99% of 2249.97) ÷ 35.98 = ?

What is the value of sin 300°?

What is the x-intercept of line joining (4, 2) and (6, 3)?

A triangular prism has 9 edges. How many vertices does it have?