Question 1153936
.
<pre>

Let x be the total number of children.


Then the equation is


    0.3x - 0.25x = 20


saying that "20 more children chose grape than chose apple".


From the equation,


    0.05x = 20,

    x     = 20/0.05 = 2000/5 = 400.


<U>ANSWER</U>.  400 children.
</pre>