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Tag Archives: 3-digit Numbers
3-digit Num3ers w/ consecutive digits
123 + 132 + 213 + 231 + 312 + 321 = 1332 (123 + 132 + 213 + 231 + 312 + 321)/2 = 666 (123 + 132 + 213 + 231 + 312 + 321)/3 = 444 (123 … Continue reading
Deleting the middle digit of 3-digit/5-digit numbers
(1) Let N be a 3-digit number (whose first digit is non-zero) and let M be the 2-digit number formed from N by deleting its middle digit N = abc … Continue reading
Posted in Number Puzzles
Tagged 3-digit Numbers, 5-digit number, Delete middle digit
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3-digit Num3ers N=abc, f(N)=a+b+c+a*b+a*c+b*c+a*b*c
N = abc, f(N) = a + b + c + a*b + a*c + b*c + a*b*c Can you find a 3-digit number … Continue reading
Consecutive integers divisible by 3,5,7,9
Let’s look for consecutive numbers that are divisible by 3, 5, 7, 9 in that order (1) 3-digit numbers: 159 = 3 * 53 … Continue reading
Num3ers formed by its digits
132 = 13 + 31 + 12 + 32 + 21 + 23 123 = 132 – (1 + 2^3) 312 = … Continue reading
3-digit numbers ABC = k*(A + B + C)
To find all 3-digit numbers abc such that 100*a + 10*b + c = k*(a + b + c) = k*a + k*b + k*c For example, k = 11 198 … Continue reading
Products of 3-digit Num3ers are pandigital
For example, The 3-digit number 107 is multiplied by three different digits 3, 7, 8 107 * 3 = 321 107 * 7 = 749 107 * 8 = 856 The 3 products … Continue reading
Concatenation puzzle: when (A || B) / B is an integer
Concatenation is the joining of two numbers by their numerals. That is, the concatenation of 444 and 777 is 444777. Concatenation of numbers A and B is denoted A || … Continue reading
A 3-digit num3er divisible by 7
Let abc be 3-digit number. abc is divisible by 7. Prove that 7 can be cancelled out of the fraction bc + 16*a ——————– bc – 61*a … Continue reading
abc * xyz = ax * by * cz
abc and xyz are 3-digit numbers. ax, by and cz are 2-digit numbers. For example, 567 * 432 = 54 * 63 * 72 = 244944 Here’s a … Continue reading
