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CAT 1996 — QA Question 8

Composite FunctionsEasy
Passage / Data

Direction: Answer the questions based on the following information.

A, S, M and D are functions of x and y, and they are defined as follows.

A(x, y) = x + y

S(x, y) = x – y

M(x, y) = xy

D(x, y) = xy, y ≠ 0

What is the value of S[M(D(A(a, b), 2), D(A(a, b), 2)), M(D(S(a, b), 2), D(S(a, b), 2))]?

Answer & solution

  • A

    a2 + b2

  • ab

  • C

    a2 - b2

  • D

    ab

Solution

S[M(D(A(a,b),2),D(A(a,b),2)),M(D(S(a,b),2), D(S(a, b),2))]

= S[M(D((a + b),2),D((a + b),2)),M(D((a – b),2),

D((a – b),2))] = S[M{(a+b)2,(a+b)2],M{(a-b)2,(a-b)2}}

=S[{(a+b)2]2,{(a-b)2}2={(a+b)2}2-{(a-b)2}2}

= 4ab2=ab

CAT 1996 QA Q8: What is the value of S[M(D(A(a, b), 2), D(A(a, b), 2)), M(D(S(a, b), 2), D(S(a, b), 2))]? — Solution | TheCATExam