Source: Princeton Review
How many perfect squares are less than the integer d?
1) \(23 < d < 33\)
2) \(27 < d < 37\)
The OA is B
How many perfect squares are less than the integer \(d\)?
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The best way to approach this problem is to test cases:
How many perfect squares are less than the integer d?
1) 23 < d < 33
if d = 32, there are 5 perfect squares less than d: 1, 4, 9, 16, 25
if d = 24, there are 4 perfect squares less than d: 1, 4, 9, 16
Insufficient
2) 27 < d < 37
if d = 36, there are 5 perfect squares less than d: 1, 4, 9, 16, 25. Be careful! We can't actually count 36 itself, because we're looking for "less than d"
if d = 28, there are 5 perfect squares less than d: 1, 4, 9, 16, 25
Since we get a result of 5 for any integer in this range, this statement is sufficient.
The answer is B.
How many perfect squares are less than the integer d?
1) 23 < d < 33
if d = 32, there are 5 perfect squares less than d: 1, 4, 9, 16, 25
if d = 24, there are 4 perfect squares less than d: 1, 4, 9, 16
Insufficient
2) 27 < d < 37
if d = 36, there are 5 perfect squares less than d: 1, 4, 9, 16, 25. Be careful! We can't actually count 36 itself, because we're looking for "less than d"
if d = 28, there are 5 perfect squares less than d: 1, 4, 9, 16, 25
Since we get a result of 5 for any integer in this range, this statement is sufficient.
The answer is B.
Ceilidh Erickson
EdM in Mind, Brain, and Education
Harvard Graduate School of Education
EdM in Mind, Brain, and Education
Harvard Graduate School of Education