Data Sufficiency

Hi himu,

It sounds like you understand the key to this question (was money deposited and/or removed during the month).

We're told that a bank will charge a serve fee if a checking account balance falls below $100. We're then asked if the bank charged a fee on Beth's account last month. This is a YES/NO question.

TESTing VALUES can help you to not "get lost" in the question:

Fact 1: Last month, $1,000 was withdrawn from Beth's account.

If there was $1,050 to begin with and no money was deposited...
$1,050 - $1,000 = 50 and the answer to the question is YES

If there was $2,000 to begin with and no money was deposited....
$2,000 - $1,000 = $1,000 and the answer to the question is NO
Fact 1 is INSUFFICIENT

Fact 2: The beginning balance was $500

If no money was withdrawn, then...
$500 - 0 = $500 and the answer to the question is NO

If $450 was withdrawn, then....
$500 - $450 = $50 and the answer to the question is YES
Fact 2 is INSUFFICIENT

Combined, we know:
The starting balance = $500
$1,000 was withdrawn

However, we know NOTHING about money that may have been deposited.
IF.....
$1,000 was deposited, then $500 + 1,000 - 1,000 = $500 and the answer to the question is NO

$550 was deposited, then $500 + 550 - 1,000 = $50 and the answer to the question is YES
Combined, INSUFFICIENT

Final Answer: E

GMAT assassins aren't born, they're made,
Rich

himu wrote:Beth's bank charges a service fee on a regular checking account for each month in which the balance on the account falls below $100 at any time during the month. Did the bank charge a service fee on Beth's regular checking account last month?

1) During last month, a total of $1,000 was withdrawn from Beth's regular checking account.

2) At the beginning of last month, Beth's regular checking account balance was $500.

Target question: Did the bank charge a service fee on Beth's regular checking account last month?

REPHRASED target question: Did Beth's balance ever go below $100?

Statement 1: During last month, a total of $1,000 was withdrawn from Beth's regular checking account.
Were given no information about her starting balance, so we can't say whether or not Beth's balance went below $100
INSUFFICIENT

Statement 2: At the beginning of last month, Beth's regular checking account balance was $500.
Were given no information about how much money Beth withdrew over the month, so we can't say whether or not Beth's balance went below $100
INSUFFICIENT

Statements 1 and 2 combined
Here are two CONTRADICTORY scenarios that could have occurred:
Case a: Beth begins the month with $500. On Day 2, she deposits $500 more. On Day 3, she withdraws $1000. In this case, Beth's balance went below $100.
Case b: Beth begins the month with $500. On Day 2, she deposits $10,000 more. On Day 3, she withdraws $1000. No other deposits or withdrawals are made for the rest of the month. In this case, Beth's balance NEVER went below $100.
Since we cannot answer the REPHRASED target question with certainty, the combined statements are NOT SUFFICIENT

Answer = E

Cheers,
Brent