Tag Archives: Digits
#puzzle : Digits — (Part 2)
(1) Determine the smallest positive integer N such that, if the digit 7 is written after it and the digit 2 in front of it, the result is 91 times … Continue reading
#puzzle | moving and deleting digits – (Part 1)
(1) Find the smallest positive integer N with the following property: If the first digit of N, which is 9, is moved to the end of the number, the resulting integer is 1/7-th … Continue reading
Powers N^x; N= 2,…, 99 and x=2,…,10
Numbers N = 2, 3, … ,99 and x = 2, 3, …, 10 Here’s a partial list of powers of numbers N that can be expressed in terms of their digits. Please complete … Continue reading
Num3ers equal to the product of its first 3 and last 3 digits
Find all numbers N, such that N is equal to the product of its first 3 and last 3 digits. For example, if N is a 4-digit number, abcd, then find N such that … Continue reading
Expressing Num3er 24 out of other num3ers
Given the number N = 24 construct out of several other numbers, by taking the numbers and performing the basic operations. For example, Making 24 out of …. (0, 0, 0, 0) (0! + 0! + 0! … Continue reading
AB * AA = BAAB and ABCD * 4 = DCBA
Let AB & AA be 2-digit numbers. AB * AA ———- BAAB AB * AA = BAAB (10*A + B)(10*A + A) = 11*A*(10*A + B) = 110*A^2 + … Continue reading
Digits Reversed (Part 2)
Consider the 4-digit number, 2047 Reverse the 2-nd & 3-rd digit to get, 2407 2047 can be expressed as the product of 23 and 89 2047 = 23 * 89 And, 2407 … Continue reading
Delete the Middle Digit from the Product of Two Integers
12 * 42 = 504 = 21 * 24 Delete the middle digit from the product, and you get: 54 And, 12 + 42 = 54 Note that 21 + 24 … Continue reading
Delete the First Digit from the Product of Two/Three Integers
12 * 92 = 1104 Delete the first digit from the product, and we get: 104 12 + 92 = 104 14 * 78 = 1092 Delete the first digit from the product, and we get: 092, that … Continue reading
Num3ers equal to 4-th power to sum of its digits
(2 + 4 + 0 + 1)^4 = 2401 = 7^4 2 + 4 + 0 + 1 = 7 (2 + 3 + 4 + 2 + 5 + 6)^4 = 234256 … Continue reading
