Question

A 3 B

X B

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2 1 7 B

What is the value of A if each letter represents a different digit ?

• A. 3
• B. 4
• C. 5
• D. 7

Answer 1

Answer: (B)

4

B X B gives B in its units place. So B must be 1 or 5 or 6
if B = 1, B X B = 1 X 1 = 1 in units place and B X 3 = 3 in ten's place of result. But Tens place is 7. So cannot be 1.

Use B = 5

B X B = 5 X 5= 25 --- Units place

B X 3 + carry-two = 15+ 2 = 17 ---Tens Place

B X A +carry-one = A X 5 + carry-one = 21 ---Hundred's place

so A = 4

thus

4 3 5

X 5

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2 1 7 5

Option B.