Question

If the elements on the ground floor of a number tower are 2, 6 and 10 and that on the first floor are 8 and 16, then the top floor element is .

• A. 18
• B. 20
• C. 24

Answer 1

The correct option is C 24


We can see that
$2+6=8$ and
$6+10=16.$

A number on the first floor is equal to the sum of the two numbers beneath it on the ground floor.

Similarly, the number on the topmost floor is equal to the sum of the numbers on the first floor.

$8+16=24$

$\therefore$ The top floor element is 24.