Quantitative Aptitude - Arithmetic Ability Questions

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

What is the ratio of simple interest earned on certain amount at the rate of 12% for 6 years and that for 12 years?

What is the simplified value of tan (θ/2) + cot (θ/2)?

A merchant changed his trade discount from 25% to 15%. This would increase selling price by

Ramesh and Rahman can do a work in 20 and 25 days respectively. After doing collectively 10 days of work, they leave the work due to illness and Suresh completes rest of the work in 3 days. How many days Suresh alone can take to complete the whole work ?

What is the difference (in Rs) between the compound interests on Rs. 4000 for 1 year at 12% per annum compounded yearly and half-yearly?

A person while buying a dress on sale spends Rs. 45 and saves Rs. 5, what is the percentage of his savings?

If the three numbers in the ratio 3:2:5 be such that the sum of the squares is equal to 1862 then which number is the middle one.