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Comment on Sum of 4 Unknown Digits
How about we use A=9, C=-1
Nice idea, but there are no
Nice idea, but there are no negative digits.
There are 10 digits altogether: 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9
To hard to do in a short time
Agreed! It's a tricky
Agreed! It's a tricky question.
why cant c=2?
Once we know that B = 1 and D
Once we know that B = 1 and D = 0, it MUST be the case that C = 9
If it were the case that C = 2, then we must be able to assign different values for A, B, C and D so that the original sum works. Can you do that with C = 2?
Cheers,
Brent
Hey I didn't get why and how
The question tells us that a
The question tells us that a 2-digit number PLUS another 2-digit number yields a 3-digit SUM.
Let's examine some examples of when this occurs:
50 + 80 = 130
29 + 72 = 101
99 + 99 = 198
63 + 71 = 134
18 + 85 = 103
Notice that, in all of these cases, the hundreds digit is 1.
In fact, in this situation, the 3-digit number will ALWAYS have hundreds digit 1.
For this reason, we know that B = 1
Does that help?
Cheers,
Brent
When you say, "In fact, in
Oops my bad. I changed my
Oops my bad. I changed my response above to have "hundreds" (not unit)
Thanks for the heads up!
My logic to remember:
The sum of any two 2-digit numbers can never exceed 198, so, the first digit of the sum must be 1.
That's perfectly logical
That's perfectly logical reasoning!
Hello brent,
Can you please let me know, where can I find more similar practice questions?
This isn't a very common
This isn't a very common question type, but I have found a few similar questions to practice:
- https://gre.myprepclub.com/forum/if-a-b-and-c-represent-different-digits...
- https://gre.myprepclub.com/forum/gre-quantative-sum-a-b-c-and-d-represen...
- https://gre.myprepclub.com/forum/in-the-following-correctly-worked-addit...
Cheers,
Brent
Hi dear Brent,
Could you please give us more than three questions of this type, at least 10 practice questions?
Thanks a ton
This question type isn't that
This question type isn't that common. Here's what I could find on GRE Prep Club:
- https://gre.myprepclub.com/forum/in-the-following-correctly-worked-addit...
- https://gre.myprepclub.com/forum/if-a-b-and-c-represent-different-digits...
- https://gre.myprepclub.com/forum/in-the-correctly-calculated-subtraction...
- https://gre.myprepclub.com/forum/digit-problem-10496.html
Cheers,
Brent
Thanks a ton, I appreciate
What If a=7 b= 6 c=8 d=4
A+B+C+D=25
76
68
---
144
---
Close but, those numbers don
Close but, those numbers don't meet the conditions of the question.
The sum must be BDD
Using your values, BDD = 644 (not 144)