A fraction is greater than its reciprocal by 9/20. What is the fraction?

If x/2 - [4(15/2 - x/3)]/3 = -x/18, then what is the value of x?

An amount fetched a total simple interest of Rs. 3200 at the rate of 6.25 %/yr in 4 years. What is the amount (in Rs)?

If a boat goes a certain distance at 30 km/hr and comes back the same distance at 60 km/hr. What is the average speed (in km/hr) for the total journey?

A number is increased by 84, it becomes 107% of itself. What is the number?

A wholesaler sells a jacket to a retailer at a profit of 5% and the retailer sells it to a customer at a profit of 10%. If the customer pays Rs. 4158, what had it cost (in Rs) to the wholesaler?

The average marks of 40 students in an examination was 25. It was later found that the marks of one student had been wrongly entered as 73 instead of 37. What is the value of correct average?

The ratio of present ages of R and S is 11:17. Before 11 years the ratio of their ages was 11:20. What is R's present age (in years)?