Question

How many positive integers less than 450 can be formed using 1,2,5 and 6 for it's digits, with each digit being used only once?

Answer 1

6 numbers will form by using 1,2,5,6

Answer 2

Answer:

Step-by-step explanation:

450

3 digit number:

100th place=2 chance

10th place=3 chance

unit's=2 chance

p1=2*3*2=12

2 digit number:

10th place=4

units=3

p2=4*3=12

similarly

p3=4

.'. p=p1+p2+p3=12+12+4=28