A bank PIN is a string of four digits, each digit 0-9. (a) How many choices are there for a PIN if the last digit must be odd? M
ake sure to explain your answer. (b) How many choices are there for a PIN if the last digit must be odd and all the digits must be different from each other? Make sure to explain your answer.
a) there are four different slots, and for the first three slots there are a possibility for 10 different numbers and in the last slot there can only be 5 different numbers. So you get 10 x 10 x 10 x 5 which leaves you with 5,000 possibilities
b) the same thing as above but know you have fewer numbers 10 x 9 x 8 x5 which gives you 3,600 possibilities
To find how many miles per hour you need to divide 50 by 5 to get the number of miles per hour and do the same thing to the 2nd step and to find the difference you need to subtract the numbers. Hope it helps!!!