**Answer:**

**The number of students who prefer chocolate milk is 780 . **

**Step-by-step explanation:**

Given as :

The total number of students in the school = 1200

The percentage of students who prefer plain white milk = 35 %

Let the number of students who prefer chocolate milk = x

Now, ∵ The percentage of students who prefer plain white milk = 35 %

∴ The percentage of students who prefer chocolate milk = 100 % - 35 % = 65%

So , As The number of students who prefer chocolate milk = x

Or,** 65 % of total number of students in school = x**

So, x = × 1200

or, x =

∴ x = 780

So, the number of students who prefer chocolate milk = x = 780

And students who prefer plain white milk = 1200 - x = 1200 - 780 = 420

**Hence, The number of students who prefer chocolate milk is 780 . Answer**