Directions (Set of 5 questions): What will come at the place of question mark (?) in the following number series?
20, 20.7, ?, 21.4, 18.6, 22.1
Solution
$20+ (0.7\times 1) = 20.7$
$20.7-(0.7\times 2)=19.3$
$19.3+(0.7\times 3)=21.4$
$21.4-(0.7\times 4)=18.6$
$18.6+(0.7\times 5)=22.1$