Both a, b, and c are 3-digits integers, where a=b+c. Is the

Question

. Both a, b, and c are 3-digits integers, where a=b+c. Is the hundreds' digit of number a equal to sum of that of b and c?
1). Tens' digit of a=tens' digit of b+tens' digit of c
2). Units' digit of a=units' digit of b + units' digit of c

mdfrahim · Answer

C.

Let the number be as follows
a = 100D + 10E + F
b = 100G + 10H + I
c = 100J + 10K + L

As per question
a = b + c
100D + 10E + F = (100G + 10H + I) + (100J + 10K + L)

stmt 1.
E = H + K
Not suff. as the sum of LHS and RHS can be influenced by G,J,I and L.

Stmt. 2
F = I + L
Not suff. due to same reason as for stm. 1.

Combine
100D + 10E + F = 100G + 100J + 10h + 10K + I + L
100D + 10E + F = 100G + 100J + 10(h+k) + F
100D + 10E + F = 100(g+j) + 10E + F
Lookign at the above eq.
100D = 100(G+J)
or d = G+J.
Hence suff.

Pls. tell the OA.

GMATaddict · Answer

This is basically a problem that asks us to determine whether there were any numbers carried over from the previous units in the addition process.

1 - Not enough. We know if the tens' digits do not add up to 10, then nothing will be carried over. We know the tens' digits of B & C do not add to 10, but we don't know whether anything carried over from the addition of the units' digits, which might in turn push the sum of the tens' digits over 10.
2 - Also not enough for the same reason above. We know the addition of the units' digits won't carry over to the tens, but we don't know anything about the tens' digits.

Combined: Enough, we know neither the units nor the tens will carry over additional numbers, so the sum of the hundreds' digits will not include anything carried over.

rashminet84 · Answer

I think ans is A

Statement 1 can only be true when there are no carry forwards from units to tens, and also from tens to hundreds. Though i have not checked out all the alternatives as it would take a lot of time, i personally feel sufficiently confident about this, and would rather have it answered wrong than waste time in attempting to check all alternatives.

If there are no carry forwards from tens to hundreds, the sum of hundreds digits of b and c will be equal to that of a.

skpMatcha · Answer

the only thing that I can conclude from this statement is , nothing got carried from units place...but I cant tell whether anything got carried over to the hundreds place..

281
+372
------
 653 <-- here tens digit of the result is still equal to the tens digit of b and tens digit of c

one more case

231
+321
------
 552 <-- here nothing is carried forward still the statement 1 holds good.

I would say the answer be E.

rashminet84 · Answer

tens digit is not equal to that of b+c

8+7 = 15 and not 5; and 15 is not one single digit. So no carry forward is ensured.

skpMatcha · Answer

Thanks for the explanation. Looks like these notions are unique to GMAT.

like rounding to nearest number cant be recursive and only the digit next to the rounding position is rounded && and the example as this thread..

cipher · Answer

I also think it should be A as there is no carry forward from the tens digit. Anyway whats the OA ?

Cheers

defoue · Answer

Hi Guys, can someone explain why answer is "A"?
Thx in advance

Both a, b, and c are 3-digits integers, where a=b+c. Is the

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards