The length of segment AB is 40 cm. Points C and D divide segment AB into segments AC, CD and DB. The length of the segment CD

The length of segment AB is 40 cm. Points C and D divide segment AB into segments AC, CD and DB. The length of the segment CD is 4 cm longer than the length of the segment AC, but 2 times less than the length of the segment DB. Find the length of the segment AC.

Let x (cm) be the length of the segment CD,
Then x-4 (cm) the length of the segment AC
And 2 * x (cm) DB segment length
x + x-4 + 2x = 40
4x-4 = 40
4x = 44
x = 11
11 cm is equal to CD segment
11-4 = 7 cm is equal to segment AC
Answer: 7 cm