No. of digits to be filled at one’s place =3 No. of digits to be filled at 10’s place =5 No. of digits to be filled at 100’s place=4 ∴Total no. of digits formed=3×5×4=60 If zero is at 100’s place; Then; no. of digits to be filled at one’s place=2 & no. of digits to be filled at 10’s place=4 ∴No. of digits formed with zero at 100’s place=1×2×4=8 ∴Required no. of digits formed=60−8=52.