Numbers - General Aptitude

Q1:

(935421 x 625) = ?

A 575648125

B 584638125

C 584649125

D 585628125

ANS:B - 584638125

935421 x 625 = 935421 x 54 = 935421 x 10 4
2
= 935421 x 104 = 9354210000
24 16
= 584638125