Quantitative Aptitude - Arithmetic Ability Questions

50 litre mixture of water and alcohol contains 10% alcohol. How much more alcohol must be added to make the strength of alcohol 40% in the new mixture?

If cos4θ-sin4θ=13 then the value of tan2θ is

The least number, which when divided by 5, 6, 7 and 8 leaves a remainder 3 in each case, but when divided by 9 leaves no remainder, is:

What is the average of first 30 multiples of 9?

If the selling price of an article is doubled, then its loss percentage gets converted into the equal profit percentage. What is the loss percentage?

If  2x+14x = 1, then the value of  x2+164x2is

Given: 6x + 2(6-x) > 2x -2 < 5x/2 - 3x/4; then x can take which of the following values?

If ax + by = 1 and bx + ay = 2aba2+b2 then x2+y2a2+b2 is equal to