CAT Practice : Coordinate Geometry

Take Geometry, add one unit of algebra; take a diagram, explain it with x's and y's. For the purists, it is geometry without the romance, for the pragmatists it is Geometry with expanded scope.

Coordinate geometry and greatest integer function

    Q.3: Region Q is defined by the equation 2x + y < 40. How many points (r, s) exist such that r is a natural number and s is a multiple of r?
    1. 84
    2. 92
    3. 105
    4. 72

 

  • Correct Answer
    Choice B. 92

Detailed Solution

When r = 1, s can take 37 values

When r = 2, s can take 17 values

When r = 3, s can take 11 values

When r = 4, s can take 7 values

When r = 5, s can take 5 values

When r = 6, s can take 4 values

When r = 7, s can take 3 values

When r = 8, s can take 2 values

When r = 9, s can take 2 values

When r = 10, s can take 1 values

When r = 11, 12, 13 s can take one value each.

Totally, there are 92 values possible.

Correct Answer: 92 values



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More questions from Coordinate Geometry

  1. Straightline Shortest distance
  2. Coordinate Geometry and Probability
  3. Cogeo and greatest integer function
  4. Angle bisector theorem
  5. Area under curve
  6. Area of segment
Take Geometry, add one unit of algebra; take a diagram, explain it with x's and y's. For the purists, it is geometry without the romance, for the pragmatists it is Geometry with expanded scope.