UPSC Prelims 2015·CSAT·Quantitative Aptitude·Number System

If ABC x DEED = ABCABC; where A, B, C, D and E are different digits, what are the values of D and E?

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  1. AD = 2,E = 0
  2. BD = 0,E = 1
  3. CD = 1,E = 0Correct
  4. DD = 1,E = 2

Explanation

The equation is ABC x DEED = ABCABC. We can rewrite ABCABC as ABC x 1000 + ABC, which simplifies to ABC x (1000 + 1) = ABC x 1001. Substitute this back into the original equation: ABC x DEED = ABC x 1001 Since ABC is a three-digit number, it is not zero. We can divide both sides by ABC: DEED = 1001 Now, by comparing the digits of DEED with 1001, we can determine the values of D and E: D = 1 E = 0 E = 0 D = 1 So, D = 1 and E = 0. The problem states that A, B, C, D, and E are different digits. Our derived values D=1 and E=0 are different from each other. The remaining digits A, B, C can be chosen from the other available digits (2, 3, 4, 5, 6, 7, 8, 9) to satisfy the condition. Let's check the options: A) D = 2, E = 0: DEED would be 2002, not 1001. B) D = 0, E = 1: DEED would be 0110 (or 110), not 1001. C) D = 1, E = 0: DEED would be 1001, which matches our derivation. This is correct. D) D = 1, E = 2: DEED would be 1221, not 1001. Therefore, the values of D and E are 1 and 0, respectively. The final answer is C.
Quantitative Aptitude: If ABC x DEED = ABCABC; where A, B, C, D and E are different digits, what are the values of D and E?

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