Business Mathematics

221. Given 5x +3y = 8, -2x +5y =10 and 3x +βy =4 . Equation I consistent for

  1. β =46/33
  2. β =47/33
  3. β =45/33
  4. β =41/33
Correct answer: (B)
β =47/33

222. Solve x +2y +3z =4, 2x +3y +8z =7 and x –y -9z =1 using Gauss-Jordan method

  1. x=1, y=2, z=3
  2. x=0, y=1, z=3
  3. x=2, y=1, z=0
  4. x=3, y=0, z=1
Correct answer: (C)
x=2, y=1, z=0

223. Solve 2a +4b =7
4a +3b =1

  1. a =-5, b=3
  2. a= -2, b=4
  3. a= -1.7, b=2.6
  4. a=-2.5, b=3.4
Correct answer: (C)
a= -1.7, b=2.6

224. Solve 3x +4y +5z =18
2x –y +8z=13
5x -2y +7z =20

  1. x=2, y=1, z=2
  2. x=3, y=1, z=1
  3. x=1, y=2, z=1
  4. x=2,y=1, z=1
Correct answer: (B)
x=3, y=1, z=1

225. Solve 2x + 5y = -10
-2x + 4y = 0

  1. x = -10/9 y= -20/9
  2. x= -8/9 y= -10/9
  3. x= -20/9 y= -10/9
  4. x= -10/9 y= -8/9
Correct answer: (C)
x= -20/9 y= -10/9

226. A survey showed that 63 % of the Americans like cheese whereas 76 % like apples. If x % of Americans like both cheese and apples, then find the range of x?

  1. 0 ≤ x ≤ 23 %
  2. 0 ≤ x ≤ 39 %
  3. 4 ≤ x ≤ 35 %
  4. 6 ≤ x ≤ 33 %
Correct answer: (B)
0 ≤ x ≤ 39 %

227. If x ≠ 1, and f(x) = x + 1 / x – 1 is a real function, then f(f(f(2))) is

  1. 1
  2. 2
  3. 3
  4. 4
Correct answer: (C)
3

228. If f(x) = + , then f(x) is

  1. An odd function
  2. An even function
  3. Neither odd nor even
  4. None of the above
Correct answer: (B)
An even function

229. If A = {1, 2, 4} B = {2, 4, 5}, C = {2, 5} then (A – B) x (B – C)

  1. {(1, 2), (1, 5), (2, 5) }
  2. {(1, 4)}
  3. (1, 4)
  4. None of these.
Correct answer: (B)
{(1, 4)}

230. Let R be a relation N define by x + 2y = 8 . The domain of R is

  1. {2,4,8}
  2. {2,4,6,8}
  3. {2,4,6}
  4. {1,2,3,4}
Correct answer: (C)
{2,4,6}
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