Quantitative Aptitude - Arithmetic Ability Questions

A mixture contains 25% milk and rest water. What percent of this mixture must taken out and replaced with milk so that in mixture milk and water may become equal. 

A six-sided die with faces numbered 1 through 6 is rolled three times. What is the probability that the face with the number 6 on it will not face upward on all the three rolls?

12 year old Manish is three times as old as his brother Rajeev. How old will Manish be when he is twice as old as Rajeev ?

In the following question, four number pairs are given. The number on left side of (–) is related to the number on the right side of (–) with some Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives.

In a mixture of three varities of oils , the ratio of their weight is 4 : 5 : 8. If 5 kg of oils of the first variety, 10 kg of the second variety and some quantity of oils of the third variety are added to the mixture, the ratio of the weights of three varieties of oils becomes as 5 : 7 : 9 in the final mixture, find the quantity of third variety of oil was ? 

A circular piece of thin wire is converted into a rhombus of side 11 cm. Find the diameter of the circular piece?

Rajitha invested 25% more than Santhosh. Santhosh invested 30% less than Raju, who invested Rs. 6,000. What is the ratio of the amount that Rajitha invested to the total amount invested by all of them together ?