Question
Average weight of all the people in a group is 55 kg.
When two people of weight 63 kg and 77 kg left the group, average weight reduces by 1.5 kg. Find the number of people in the group now.Solution
Let the number of people initially be 'n'.
So, 55n - 53.5 × (n - 2) = 63 + 77
Or, 55n - 53.5n + 107 = 140
Or, 1.5n = 33
Or, 'n' = 22
Required number of people = 22 - 2 = 20
P invests Rs. 5,500 on compound interest at 16% p.a. (compounded semiannually) for 1 year. Find the interest earned by 'P'.
Krishna invests a certain amount at an annual simple interest rate of 9% for 2 years. The total amount he receives after this period is then reinvested ...
Atul has Rs.600 with him. He invested 30% of the amount at 5% p.a. for 6 years and rest at 15% p.a. for 4 years. Find the sum of simple interests receiv...
A person invested Rs. 75,000 at an annual compound interest rate of 12%, compounded annually for 12 months. How much more profit would he have earned if...
The interest earned on investing Rs. 1000 for 2 years at the rate of 20% p.a., compounded annually, is used to purchase an article. If the article is la...
The simple interest on a sum of money is 4/25 of the sum. If the number of years is numerically half the rate per annum, then find the rate percent per ...
Rs. 2,800 increases to Rs. 3,640 in 4 years at a simple interest rate of r% per annum. If Rs. 7,000 is put at 2r% per annum for 1 year, how much interes...
Suresh earned an interest of Rs. 1548 on principal amount of Rs. 4800 at some rate of compound interest in 2 years. How much more/less interest would he...
Akshay invested Rs. 1200 in two schemes P and Q in the respective ratio of 7:3. Scheme P and Q are offering simple interest at the rate of 10% per annum...
Simple interest received at the rate of 20% p.a. for 6 years on a principal amount of Rs. 9000 is twice of the simple interest received at 10% p.a. for ...
Relevant for Exams:
