College of Admission Tests Multan

Solving Questions

Solve the question of Solving Questions and select the option from the choices A through D/E. Check your Answer and view the explanation.

Question: 1

Column A Column B
ab = - 40
(a + b )2(a - b )2
  • A if the quantity in Column A is greater.
  • B if the quantity in Column B is greater.
  • C if the two quantities are equal.
  • D if the relationship cannot be determined from the information given.

  Show/Hide Explanation 

Correct Answer: B

No video yet
Did you memorize the expanded forms of these two expressions: (a + b)2 = a2 + 2ab + b2 and (a – b)2 = a2 – 2ab + b2? Now cancel the quantities that are identical in both columns by slashing off a2 and b2. You’re left with +2ab, which would be –80, compared to –2ab, which would be +80 (because a negative times a negative is a positive). Correct Answer: B.