CAT Quantitative Ability Questions | CAT Algebra questions
CAT/2003
Question . 122
Which one of the following conditions must p, q and r satisfy so that the following system of linear simultaneous equations has at least one solution, such that p + q + r ≠ 0 ?
x + 2y 3z = p ; 2x + 6y 11z = q ; x 2y + 7z = r
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Explanatory Answer
Method of solving this CAT Quantitative Ability Question from Algebra question
(a) Solving from the choices,
5p - 2q - r = 0
→ 5(x + 2y - 3z) -2(2x + 6y - 11z) - (x - 2y + 7z) = 0
→ (5x + 10y - 15z) - (4x + 12y - 22z) - (x - 2y + 7z) = 0
→ 0 = 0
For no other choices above condition is satisfied, hence option (a) is correct.