Mary borrowed $1800 from Elena at an interest rate of 12% per annum (compound interest) for 36 months. What will be the approximate value of the amount paid by Elena after 36 months if the interest is calculated quarterly?

If the principal amount is $8000 and the rate of interest is 4% per annum computed half yearly, then in how many months will the compound interest of $659.46 be generated?

The length(l) and breadth(b) of a cistern is 0.78 kilometers and 699.9 cubits respectively. The level of water in the cistern is up to 106 meters and 35 centimeters. What is the approximate area of the wet surface of the cistern where area of wet surface = 2(bh + lh) + lb?

Complete the following statement: There are ________________ in 1049/72 days.

Andrew takes 3 hour 40 minutes more than Nina in covering a distance of 19.88 miles. If Andrew increases his speed by three times of his original speed then he would take 80 minutes less than Nina. What is Andrew's original speed (approximate)?

Mary is thrice as old as Lisa and Ian is 60 months older than Mary. If the sum of ages of Mary, Lisa, and Ian is 63 years and 4 months, then what is Mary's age?

Mark invested $5600 in a simple interest scheme for 4 years and 6 months. He lends the money thus obtained to Sam at the rate of 5% (compound interest) for 1 year. The interest is calculated half yearly and the duration of the loan is 1 year. If the amount obtained after one year is $8535.56, then what is the approximate rate of simple interest?

In how many weeks will a principal of $4600 amount to $5290 at a simple interest rate of 2.5% per annum.

6 years later Mathew's age will be 438288 hours. If the present ratio of Ian's and Mathew's age is 9:11, then what is the present age of Ian?

If the speed of a motorcycle is 179 miles/hour, then how much time (approximately) will it take to cover a distance of 9840 meters?

The current age of Elena is four times the age of Nina. After 84 months, the ratio of ages of Elena and Nina will be 5:3. What will be the ratio after 11 years?