Question 459211

No. of 4 digit numbers where  first digit is 4,5,6 or 7.

4* 6P3 =  4 * 120 = 480

No. of 4 digit numbers where first digit is 3..

second place can be filled by 4,5,6,or 7.

no. of possible numbers = 4*5P2 = 4 * 20 = 80 


total no. of possible numbers formed from 1,2,3,4,5,6 and 7 

and greater than 3400 =   480 + 80 = 560 


Note- repetition is not allowed here.