2100 is the right answer...
Using number 3, 5, 6, 7 and any number of mathematical operators can you form number 100.
Note: you can make number 100 in many ways.
Calculate the number of ordered triples (A1, A2, A3) such that:
A1 ∪ A2 ∪ A3 = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} A1 ∩ A2 ∩ A3 = ∅
Write your answer as 2a3b5c7d where a, b, c, d are non-negative integers.
How many 3-digit numbers can be formed from the digits 2, 3, 5, 6, 7 and 0, which are divisible by 5 and none of the digits is repeated?