Quiz Discussion

$\frac{{{{\left( {a - b} \right)}^2} - {{\left( {a + b} \right)}^2}}}{{ - 4a}}{ \text{ = }}\frac{x}{y}$     On simplifying the given equations, which of the following equations will be obtained ?

• 1] xy = b
• 2] bx = y
• 3] ab = x
• 4] yb = x
• 5] ay = x

The square root of $\frac{{0.342 \times 0.684}}{{0.000342 \times 0.000171}} = ?$

• 1] 250
• 2] 2500
• 3] 2000
• 4] 4000

David gets on the elevator at the 11th floor of a building and rides up at the rate of 57 floors per minute. At the same time, Albert gets on an elevator at the 51st floor of the same building and rides down at the rate of 63 floors per minute. If they continue travelling at these rates, then at which floor will their paths cross ?

• 1] 19th floor
• 2] 28th floor
• 3] 30th floor
• 4] 37th floor

If $x = \sqrt 3 { \text{ + }}\sqrt 2 { \text{,}}$ then the value of ${x^3} - \frac{1}{{{x^3}}}$  is?

• 1]

  $10\sqrt 2$

• 2]

  $14\sqrt 2$

• 3]

  $22\sqrt 2$

• 4]

  $8\sqrt 2$

A millionaire bought a lot of hats 1/4 of which were brown. The millionaire sold 2/3 of the including 4/5 of the brown hats. What fraction of the unsold hats were brown ?

• 1]

  1/60

• 2]

  1/15

• 3]

  3/20

• 4]

  3/5

• 5]

  3/4