On January 1st Thomas deposited $2,000 into an interest bearing checki

Question

On January 1st Thomas deposited $2,000 into an interest bearing checking account. If he made no withdrawals, what was the total amount Thomas had in the checking account on December 31st of the same year?

(1) Thomas deposited an additional $4,000 throughout the year.
(2) The checking account earned 7 percent simple annual interest.

AmoyV · Answer

1. Not Sufficient.
We do not know the interest of the checking account.

2. Not Sufficient.
We do not have any information on any additional deposits in the account.

1 and 2 Not Sufficient.
We do not know when the interest is calculated. It could be possible that the interest is earned is before the 2nd deposit is made or after. In each case, the interest calculated will be different and hence the total amount at the end of the year will be different.

Answer: E

musunna · Answer

The question asks for  Total Amount  in account as on 31st December.

Statement 1 says deposited an additional $4,000 throughout the year. However no mention of interest rate. So  NOT  sufficient.

Statement 2 says the account earned 7% simple annual interest. So Total Amount on 31st Dec will be $2000*1.07 = 2140.  Sufficient.

So Option (B) wins.

The trap Point 
 Statement 1 should not consider while testing sufficiency of Statement 2.

Guilio · Answer

E.

(1) Clearly not sufficient as we have no information about the interest rate.

(2) Had I not read statement 1 before, I would have thought this is sufficient. However, we only know there were no withdrawals. What if Thomas deposited more money in the meantime? Clearly not sufficient.

Both statements also aren't sufficient as it would be essential to know the timing of the second deposit.

keats · Answer

On January 1st Thomas deposited $2,000 into an interest bearing checking account. If he made no withdrawals, what was the total amount Thomas had in the checking account on December 31st of the same year?

(1) Thomas deposited an additional $4,000 throughout the year.
(2) The checking account earned 7 percent simple annual interest.

__________________________

P = $2000 on Jan 1
Amount on Dec 31 ?

ST 1 : Additional 4000 was spread throughout the year, but we cannot account for the interest earned on (2000 + 4000). So, insufficient

ST 2 : Interest = 7%
This tells you that Interest earned will be 140 making the total amount as 2140
Sufficient.

B should be the answer.

PS: I am a bot confused because of statement A. When I solve ST II, we don't know if there is any investment made throughout the year. So, I came to B after assuming that *no investment* apart from the initial $2000 is done.

Guilio · Answer

So the question is, are we allowed to assume that there was no additional investment in statement B?

MathRevolution · Answer

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.

On January 1st Thomas deposited $2,000 into an interest bearing checking account. If he made no withdrawals, what was the total amount Thomas had in the checking account on December 31st of the same year?

(1) Thomas deposited an additional $4,000 throughout the year.
(2) The checking account earned 7 percent simple annual interest.

In the original condition, there is 1 variable(interest rate), which should match with the number of equations. So you need 1 equation. For 1) 1 equation, for 2) 1 equation, which is likely to make D the answer.
For 1), although Thomas deposited an additional $4,000, it doesn’t say when he did, which is not sufficient.
For 2), you cannot figure out the amount of money additionally deposited, which is not sufficient.
When 1) & 2), you still cannot figure out when he additionally deposited $4,000, which is not sufficient.
Therefore, the answer is E.

 For cases where we need 1 more equation, such as original conditions with “1 variable”, or “2 variables and 1 equation”, or “3 variables and 2 equations”, we have 1 equation each in both 1) and 2). Therefore, there is 59 % chance that D is the answer, while A or B has 38% chance and C or E has 3% chance. Since D is most likely to be the answer using 1) and 2) separately according to DS definition. Obviously there may be cases where the answer is A, B, C or E.

saurabhsavant · Answer

Well, is it actually a GMAT type question? Coz, if it is not stated in statement 2) if any additional deposits were made or not, then it also not stated if the interest accresdited was credited to the same account or some other account OR was there any second holder who could have taken out the money mid way etc etc ...this way the list can become endless. So ARE WE NOT SUPPOSED TO assume that if it is not written then it is not there???

MathRevolution · Answer

Hi saurabhsavant,

In the original condition, there is 1 variable(interest rate).
However, for 1), $4,000 is added, which increases the number of variables. 
Hence, the answer is E.

Happy Studying!
Math Revolution

GMATFE2025 · Answer

While attempting DS questions shouldn't we analyze the info in Statement 1 and Statement 2 as independent?

By that logic Statement 2 is sufficient, as in the question stem there is no discussion of the amount deposited throughour the year other than 2000 deposited on Jan1. And statement 2 mentions Interest Rate so we shall be able to calculate the net amount on 31st Dec.

Pl. help me getting this. It will change the course of my actions while attempting DS questions.

Bunuel · Answer

In Data Sufficiency, when you test a statement, you use only the information in the question stem plus that statement. You do not use information from the other statement. Separately, you also  cannot make unjustified assumptions  when evaluating a statement.

So here, when evaluating statement (2), assuming Thomas did not make any additional deposits during the year is an unjustified assumption. The stem only tells us he deposited $2,000 on January 1 and made no withdrawals. It does not say he made no other deposits. Without knowing whether he deposited more money later, we cannot determine the December 31 total from statement (2) alone.

On January 1st Thomas deposited $2,000 into an interest bearing checki

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GMAT Data Sufficiency (DS) Questions

On January 1st Thomas deposited $2,000 into an interest bearing checki

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