Question
At the rate of any compound interest rate, it gets
tripled in 4 years, in how many years it will become 729 times its own?Solution
Let the principal be Rs. x, then Amount = 3x As we know, A = P (1+r/100)t 3x = x (1 + r/100)4 (1+r/100) = 4√3       ...i) Again, A = 729x, P = x 729x = x (1 + r/100)t (1+r/100) = t√729    ...ii) From equation (i) 4 √3= t√729 31/4 = 36/t Compare on powers. 1/4 = 6/t t = 24 years Smart Approach-       In 4th year = 3 times.  After T years =729=36 T=4×6=24 years.
A number when reduced by 35% gives 195. Find the number?
Vishnu purchased a new plot that needed to be fenced immediately, thereby reducing the length and width of the rectangular workplace by 2% respectively....
In a city, the number of persons travelling by bike is 22.5% the number of persons travelling by metro. The number of persons travelling on foot is 40% ...
Monthly income of A is Rs. 45000 out of which he spent 30%, 22% and 24% of his total income in rent, medicine and transportation, respectively. Find his...
Ravi spends 75% of his monthly salary. If his monthly savings are Rs 6,500, what is his monthly salary?
- 'D' is 60% of 'C'. Find the percentage value of 'D' in relation to (C - D).
A value is first raised by 15% and then reduced by 40%. What is the overall percentage change in the original value?
The speed of a car is 30% more than that of a bike. Both of them start from a same point. After travelling for 7 hours, the speed of the bike is increas...
A girl spent 16% of her monthly income on clothing. Of the remaining, she spent on travel and food in the ratio of 5:2. If the difference of the income ...
- During an election, 5% of the total electorate didn’t cast their votes. The winning candidate secured 51% of the total votes and won by 1400 votes. Deter...
