Data Sufficiency

# is one operation of addition, subtraction, multiplication, or division, is 5#6=6#5？
1) 3#3=9
2) 5#4=20

*an answer will be posted in 2 days.

Max@Math Revolution wrote:# is one operation of addition, subtraction, multiplication, or division, is 5#6=6#5？
1) 3#3=9
2) 5#4=20

*an answer will be posted in 2 days.

(1) and (2) both imply the operation must be multiplication. None of the other operations work. Since multiplication is commutative, the target question must be true. Therefore, both (1) and (2) alone are sufficient.

Max@Math Revolution wrote:# is one operation of addition, subtraction, multiplication, or division, is 5#6=6#5？
1) 3#3=9
2) 5#4=20

*an answer will be posted in 2 days.

5#6=6#5 = ?

Statement 1: 3#3=9
This means # = multiplication.
Hence 5#6=6#5
SUFFICIENT

Statement 2: 5#4=20
This means # = multiplication.
Hence 5#6=6#5
SUFFICIENT

Correct Option: D

We can modify the original condition and the question. The question is essentially asking 5#6=6#5? and it can be interpreted as #=addition or multiplication?. Since the condition 1) and the condition 2) are the same, #= multiplication. The answer is yes and the conditions are sufficient. The correct answer is D.

- Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.