Answer:
The value of 50 % of number is 400 . 
Explanation:
Given as :
Let The number be x
According to statement 
30 percent of a number is 240
I.e 30 % of x = 240
Or, 
 × x = 240
 × x = 240
Or, 0.3 × x = 240 
So. x = 
 
 
∴ x = 800 
SO, The number is 800 . 
Now again 50 percent of that number = y
I.e y = 50 % of x
or, y = 50 % of 800
Or, y = 
 × 800
 × 800
Or, y = 0.5 × 800
∴ y = 400 
Hence The value of 50 % of number is 400 . Answer