$$\Large 840.003 \div 23.999$$ = ?
 A) 47 B) 8 C) 35 D) 18

 C) 35

? = $$\Large 840.003 \div 23.999$$

Using rule 3, here one number is increased and other is decreased to their nearest whole number

= $$\Large 840 \div 24 = 35$$