Question
A boy goes to school with a speed of 85 km/h and comes
back with a speed of 40 km/h. find his average speed?Solution
Since the distance travelled by a boy (going to school and coming back from school) is equal. So, average speed = 2xy/(x + y) Average speed = (2 x 85 x 40)/(85 + 40) Average speed = (2 x 85 x 40)/125 = 54.4 km/hr
A sum becomes 2.89 times ot itselt in 2 years when invested at compound interest (compounded annually). What is the annual rate of interest?
Raju invests a certain amount at an annual simple interest rate of 6% for 2 years. The total amount he receives after this period is then reinvested at ...
- An amount becomes Rs. 11,520 after 3 years at a simple interest rate of r% p.a. If the rate had been increased to (r + 5)% per annum, the same sum would be...
A sum of money gets eight times in 15 years , in how many years it will be 512 times in CI?
Yeshudas borrowed a certain amount from a Bank at an interest rate of 2.5% p.a. and after 4 years , he repaid a total amount of 46,200 to the Bank. How ...
What will be the ratio of simple interest earned on certain amount at the same rate of interest for 6 years and that for 16 years?
If the simple interest for 5 years is equal to 20% of the principal, then the interest will be equal to the principal after ________ years.
'Fatima' deposited Rs. 6,500 in a SIP at simple interest of 10% p.a. If she earned Rs. 3,900 as interest, then find the duration (in years) for which th...
A sum of Rs. 2800 is invested at simple interest for 2 years. If the rate interest for first year is 10% p.a. while 18% p.a. for second year, then find ...
A certain sum of money becomes Rs. 1300 in 1 year and 2700 in 3 years at certain rate of simple interest. Find the sum of money invested.
