how many 4 digits number can be formed with 1, 2,3,6,7,8 if each digit is used most at once? how many of these smaller than 600? ans( 360, 60)

Question

shubhamsrg · Answer

Whats your attempt ?

anonymous · Answer

my attempt?im sorry i didnt get what you meant by that :(

shubhamsrg · Answer

Did you attempt this ques on your own? What is your progress ?

anonymous · Answer

oh,yes, i managed to answer the first question which answer is 360 but the next question is tricky and thats my pproblem, i didnt get the 60 as the answer

shubhamsrg · Answer

The numbers are smaller than 600 only if the leading digit is 1,2 or 3.
Thus take 3 cases, fix 1 for the 1st digit, find possible permutations.
Do same with 2 and 3.
Add the final results.
See if it helps ?

anonymous · Answer

is this how it works? 3!x2!x1! 
but i still didnt get the answer

shubhamsrg · Answer

Just noticed, How can a 4 digit number be smaller than 600? o.O

anonymous · Answer

yeah, im having issue on that too!