Question
From a barrel that contains pure alcohol, 10% alcohol is
withdrawn and replaced with water. If the same process is repeated once more, then the quantity of alcohol remaining in the mixture would be 81 litres. Find the final quantity of water in the barrel.Solution
ATQ, Let the initial quantity of alcohol in the barrel be '100x' litres ATQ; 100x X (0.90)² = 81 Or, 81x = 81 Or, x = 1 So, original quantity of alcohol in the barrel = 100 X 1 = 100 litres Required quantity of water = 100 - 81 = 19 litres
A took a loan of Rs.5320 at simple interest of 20% p.a. and invested the same money in a scheme at simple interest of 30% p.a. Find the profit earned by...
Simple interest on a sum of Rs.5100 at some r% is for t years is Rs.918. If r and t are integers and 1 < r < t, then find the minimum simple interest ea...
A certain sum of money becomes 6 times of itself in 25 years at simple interest. In how many years does it become double of itself at the same rate of s...
A sum of Rs. 3800 is invested at simple interest for 2 years. If the rate interest for first year is 12% p.a. while 20% 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.
A certain amount invested at 16% p.a. compound interest, compounded annually, grows to Rs. 6969.6 in 18 months. What wil...
A borrowed Rs. 7500 from B for his business. How much amount A will return to B at the end of 25 months such that the sum was borrowed at simple interes...
Suppose 'S' invested Rs. 40,000 each at 12% p.a. in two different Funds for 2 years, with one Fund offering compound interest (compounded annually) and ...
Rs. 8500 is invested in scheme ‘A’ for 2 years and Rs. 6500 is invested in scheme ‘B’ for 2 years. Scheme ‘A’ offers simple interest of 13% ...
An equal sum of money is invested in two schemes which offer interest at the same rate but one at simple interest and the other at compound interest (co...
Relevant for Exams:
