Point D is marked on the segment Mn 16 cm long. Find the length of the segment MD if it is 3 times larger than the segment DN.

Given:
segment MN,
MN = 16 centimeters,
point D belongs to segment MN,
MD = 3 * DN.
Find the length of the segment MD -?
Decision:
Consider the segment MN.
Let the length of the segment DN be x centimeters, then the length of the segment MD is 3 * x centimeters. We know that MN = MD + DN. Let’s make the equation:
3 * x + x = 16;
x * (3 + 1) = 16;
x * 4 = 16 (in order to find an unknown factor, you need to divide the product by a known factor);
x = 16: 4;
x = 4 centimeters – length of the segment DN;
3 * 4 = 12 centimeters – the length of the MD segment.
Answer: 12 centimeters.