gre quantative
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26 Mar 2015, 11:40
why cant we use 0 for A AS 0 is also a digit?
8. In the following correctly worked addition sum, A,B,C and D represent different digits, and all the digits in the sum are different. What is the sum of A,B,C and D?
A. 23
B. 22
C. 18
D. 16
E. 14
Correct Answer: B
Explanation:
First you must realize that the sum of two 2-digit numbers cannot be more that 198 (99 + 99). Therefore in the given problem D must be 1.
Now use trial and error to satisfy the sum 5A + BC = 143
A + C must give 3 in the units place, but neither can be 1 since all the digits have to be different. Therefore A + C = 13.
With one to carry over into the tens column, 1 + 5 + B = 14, and B = 8.
A + C + B + D = 13 + 8 + 1 = 22