Question
In a class, the ratio of number of boys to number of
girls is 10:7. If 5 boys joined the class and 3 girls left the class, then the ratio becomes 5:3. Find the actual number of girls in the class.Solution
Let initially the number of boys and girls be 10x and 7x, respectively.
(10x + 5) : (7x − 3) = 5 : 3
Or, 3(10x + 5) = 5(7x − 3)
Or, 30x + 15 = 35x − 15
Or, 5x = 30 ⇒ x = 6
Therefore, number of girls = 7 × 6 = 42
Rahul placed Rs. 40,000 between two investment options, ‘E’ and ‘F’, for 6 years and 3 years, respectively. Option ‘E’ accrues simple intere...
A invested Rs. ‘x’ in a scheme offering compound interest of 30% p.a. compounded annually. If at the end of 2 years, interest received by A was Rs. ...
A borrowed Rs. 9500 from B for his business. How much amount A will return to B at the end of 24 months such that the sum was borrowed at simple interes...
B invested Rs. 8000 in a compound interest scheme for 2 years at an annual interest rate of x%. If he received Rs. 3520 as interest, find the rate of in...
Abhishek allocates Rs.1600 each into two different investment schemes, A and B. Scheme A provides simple interest annually at a rate of (R-2)%, while sc...
Vishal has certain sum of money with him. He invested 80% of the sum in scheme ‘X’ offering 15% p.a. simple interest for 8 years and received Rs. 20...
- Waqar borrowed Rs. ____ on compound interest at 15% p.a. compounded annually. After __ years, the rate of interest changed to 20%. At the end of 4 years, h...
A took loan from a bank at the rate of 17%p.a. simple interest. After 5 years he had to pay Rs.6800 interest only for the period. The principal amount b...
A man loans out Rs. 22,100 at a simple interest rate of 20% per annum. After 2 years, he reinvests the total amount received at an annual compound inter...
An amount is invested at a compound interest rate of 21% per annum, with compounding occurring once every 10 months. After 20 months, the interest earne...
