Quiz Discussion

If \(\frac{{x + 1}}{{x - 1}}{ \text{ = }}\frac{a}{b}  \)    and \(\frac{{1 - y}}{{1 + y}}{ \text{ = }}\frac{b}{a}{ \text{,}} \) then the value of \(\frac{{x - y}}{{1 + xy}}\)   = ?

• 1]

  \(\frac{{2ab}}{{{a^2} - {b^2}}}\)

• 2]

  \(\frac{{{a^2} - {b^2}}}{{2ab}}\)

• 3]

  \(\frac{{{a^2} + {b^2}}}{{2ab}}\)

• 4]

  \(\frac{{{a^2} - {b^2}}}{{ab}}\)

A man has Rs. 480 in the denominations of one-rupee notes, five-rupee notes and ten-rupee notes. The number of notes of each denomination is equal. What is the total number of notes that he has ?

• 1] 45
• 2] 60
• 3] 75
• 4] 90
• 5] None of these

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

\(\frac{{{{\left( {a - b} \right)}^2} - {{\left( {a + b} \right)}^2}}}{{ - 4a}}{ \text{ = }}\frac{x}{y}\)     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

(98764 + 89881 + 99763 + 66342) ÷ (1186 + ? + 1040 + 1870) = 55

• 1] 2254
• 2] 2354
• 3] 2368
• 4] 2404
• 5] None of these

There are two examinations rooms A and B. If 10 students are sent from A to B, then the number of students in each room is the same. If 20 candidates are sent from B to A, then the number of students in A is double the number of students in B. The number of students in room A is:

• 1] 20
• 2] 80
• 3] 100
• 4] 200
• 5] None of these

Find the value of \(\sqrt {248 + \sqrt {52 + \sqrt {144} } } = ?\)

• 1]

  -16

• 2]

  \(\pm 16\)

• 3]

  16

• 4]

  16.2

25 * 3.250 + 50.40 / 24.0 = ?

• 1]

  75

• 2]

  80

• 3]

  77

• 4]

  83

3.325 + 3.012 + 0.660 + 31.151 + 0.251 = ?

• 1]

  40.019

• 2]

  35.055

• 3]

  37.514

• 4]

  38.399

If x + y = 2a, then the value of

• 1] 2
• 2] 0
• 3] -1
• 4] 1