The sum of the digits of a two-digit number is 15 and the difference between the digits is 3. What is the two-digit number?

ক. 69

খ. 78

গ. 96

ঘ. cannot be determined

উত্তর: 96

ব্যাখ্যা: Let, the two-digit number = 10x + y 10x + y, where x and y are the two digits, According to the condition, x + y = 15 ...(i) x − y = 3 ...(ii) Adding the two equations (i) and (ii) we get, (x+ y) + (x − y) = 15 + 3 2x = 18 x = 9 Now, Putting the value of x in (i) we get, 9 + y = 15 y = 15 − 9 y = 6 So, the two-digit number = 10x + y = 10(9) + 6 = 90 + 6 = 96 + y = 10(9) + 6 = 90 + 6 = 96. So, the correct answer = 96

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