Question

Find the missing number in the given number tower.

Answer 1

We know that
$100+120=220.$


A number on a higher floor of the tower is equal to the sum of the two numbers beneath it on the floor just below it.

So, the numbers in the second floor will be the sum of the two numbers beneath it on the first floor.

$Missingnumber=100-45or120-65=55$


Thus, the missing number is 55.