Question
Quantity of water in a 280 litres mixture (alcohol +
water) is 40 litres less than the quantity of alcohol in it. Find the quantity of water to be mixed so that the quantity of alcohol in the mixture becomes 50% of the whole mixture.Solution
Quantity of water in the mixture = (280 – 40)/2 = 120 litres So, Quantity of alcohol in the mixture = (280 – 120) = 160 litres Total quantity of the mixture = 160 x (100/50) = 320 litres Therefore, quantity of water to be mixed = 320 – 280 = 40 litres
If (8x - 3y) = 196 and 7x:4y = 35:16, then find the value of (x² + 4y²).
Which of the following statements is correct?
I. If x = 12, y = –2 and z = –10, then x³ + y³
+ z³ = 720
II. If x + y = 48 an...
If x + 1/x = 2, find x⁷ + 1/x⁷.
If a3 — b3 = 602 and a— b = 2, then find the value of( a2 + b2)

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If 9 : 12 :: 12: x, and 28: 42:: 42: y, then the value of 2x + y is:
Two positive numbers differ by 2, and the sum of their reciprocals is 3/4. What is the larger number?