How many 3-digit numbers can be formed from the digits 1, 2, 3, 4 and 5 assuming that repetition of the digits is allowed and also when repetition is not allowed?
(i) 125
(ii) 60
How many 3-digit even numbers can be formed from the digits 1, 2, 3, 4, 5, 6 if the digits can be repeated?
108
How many 4-letter codes can be formed using the first 10 letters of the English alphabet if no letter can be repeated?
5040
How many 5-digit telephone numbers can be constructed using the digits 0 to 9 if each number starts with 67 and no digit appears more than once?
336
A coin is tossed 3 times and the outcomes are recorded. How many possible outcomes are there?
8
Given 5 flags of different colours, how many different signals can be generated if each signal requires the use of 2 flags, one below the other?
20