How many positive integers less than 600 can be formed using the numbers 1, 2, 3 and 5 for the ...
How many positive integers less than 600 can be formed using the numbers 1, 2, 3 and 5 for the digits?
Answer/Solution
84
Steps/Work
Notice that we can find the number of 2 and 3 digit numbers by just assuming the first digit can also be zero:
0 1 1
1 2 2
2 3 3
3 5 5
5 5 5
Number of possibilities = 5*4*4 = 80.
Then, just add up the number of 1 digits numbers = 4, so total is 80+4 = 84.
Answer:E
0 1 1
1 2 2
2 3 3
3 5 5
5 5 5
Number of possibilities = 5*4*4 = 80.
Then, just add up the number of 1 digits numbers = 4, so total is 80+4 = 84.
Answer:E