A vessel contains some mixture of Water and Alcohol in the ratio 2 ∶ 1. 12 liters of mixture is removed and replaced with water and the final ratio becomes 4: 1. What is the amount of Alcohol in the initial Mixture?

A boy scored 125 marks and 140 marks in the first test and the second test respectively. If the maximum mark in each test is 150, then the percentage increase in his performance is ___________.

The heights of a cone, cylinder and hemisphere are equal. If their radii are in the ratio 2:3:1, then the ratio of their volumes is:

1-[5-{2+(-5+6-2)2}] is equal to 

A man invested a certain sum in scheme A at 15% p.a. for 2 years and earned Rs 1950 as simple interest. He increased his sum by Rs. ‘x’ and invested in another scheme B at 10% p.a. C.I. for 2 years and received Rs. 1680 as compound interest. Find the value of ‘x’. 

If a=2b/3, b=2c/3, and c=2d/3, then find the ratio of b and d:

The compound interest on a certain sum of money invested for 2 years at 5 % per annum is Rs. 328. The simple interest on the sum, at the same rate and for the same period will be 

(0.5 ×5 + 0.25 ×0.5 + 0.5 × 4 + 0.5 ×0.75) is equal to-