40 cm.
let the length of the first part be 3x, second part be 4x, third part be 5x.
where x is a positive length in cm.
why 3x,4x and 5x ?
so that the ratio of lengths of the 3 parts be 3:4:5.
total length of the stick = 3x + 4x + 5x = 12x=96cm
so x=96/12 = 8cm
therefore the largest part of the stick (5x)= 5*8 =40cm

The probability of getting 0 heads in 4 tosses (or equivalently, 4 tails) is

.
So the desired probability is
4x + 4 + 4x = 180 so solve for x and it’s 22
1. 4x + 4
92
2. 88
The inverse of subtraction is addition