Zoe and Megan are making 3-digit codes.
The digit 0 is not used.
Zoe only uses odd digits.
Megan only uses even digits.
Zoe can make x more codes than Megan.
Assume that digits cannot be repeated.
Work out the value of x.
Answer:
Zoe:
Numbers she can use are 1, 3, 5, 7, 9 (ie she has 5 numbers to choose from)
So the total number of codes she can make = 5 x 4 x 3 = 60
Megan:
Numbers she can use are 2, 4, 6, 8 (ie she has 4 numbers to choose from)
So, the total number of codes she can make = 4 x 3 x 2 = 24
So Zoe can make 36 (60 –24) more codes than Megan