Question
A certain amount becomes Rs. 4200 in 4 years and Rs. 4800
in 6 years at simple interest. Find the interest earned if the same sum is invested at 20% p.a. compound interest, compounded annually for 2 years.Solution
ATQ,
Simple interest earned in two years = 4800 – 4200 = Rs. 600
Simple interest earned in 1 year = Rs. 300
So, sum invested = 4200 – 4 × 300 = 4200 – 1200 = Rs. 3000
Desired interest = [(1.20)² – 1] × 3000 = 0.44 × 3000 = Rs. 1320
The average age of X, Y, and Z is 25 years, and the average age of X and Y was 19.5 years at the time of Z's birth. If X is now 30 years old, determine ...
- In a city, the average rainfall for the first five days of a week was 98 cm, while the average rainfall for the last five days was 105 cm. If the average r...
The average score of a group of 50 students is 90. When the scores of 4 students—X, Y, Z, and W—are excluded, the average of the rest falls by 2. If...
Average weight of all the people in a group is 60 kg. When two people of weight 66 kg and 84 kg left the group, average weight reduces by 1 kg. Find the...
The average of six numbers is 8. When three new numbers are included in such a way that the first number is  twice the second and second number is thri...
The average weight of 5 students in a study group is 38 kg. If the weight of 2 mentors is also included, then the new average weight of each person (men...
The average weight of x persons is 33 kg. The average weight of (x−16) women is 45 kg, the average weight of (x−30) children ...
Komal bought 20 kg rice for Rs 30 per kg, b kg rice for Rs 35 per kg and (b + 4) kg rice for Rs 25 per kg. She mixed all type of rice together and the a...
10.5, 19, 40, 82, 166, 334
In a World Cup match, the average runs scored by Virat Kohli in his first 8 matches are 28. What should be his average score in the next two matches for...
