College of Admission Tests Multan

Principles of Data Sufficiency

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

Question: 4

What is the value of l + 2t?

(1) l + t = 4

(2) l + 3t = 9

  • Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
  • Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
  • BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
  • EACH statement ALONE is sufficient.
  • Statements (1) and (2) TOGETHER are NOT sufficient.

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Correct Answer: C

Statement (1) contains two variables and only one equation. Hence, it cannot determine the value of l + 2t. So, Statement (1) alone is not sufficient.

Similarly, Statement (2) contains two variables and only one equation. Hence, it cannot determine the value of l + 2t. So, Statement (2) alone is not sufficient.

With Statement (1) and Statement (2) together, we have two equations in two unknowns:

l + t = 4

l + 3t = 9

This system may have a solution. To find out, add the equations:

(l + t) + (l + 3t) = 4 + 9

2l + 4t = 13

l + 2t = 13/2

Hence, the statements together answer the question. The answer is (C).