Answer:
The Amount of Non-red pencil which were added to the box = 10
Step-by-step explanation:
Given as :
The number of pencils in a box = 30
The number of red pencils in a box out of 30 = 10
So , the number of Non-red pencils = 30 - 10 = 20
Again let the number of Non-red pencils which added further = x
So, now the amount of total pencil get increase to (30+x)
Among (30+x) pencils in box,25% of them are red ,
I.e The number of red pencils in a box out of (30+x) = 25% of (30+x)
And the number of Non-red pencils = 20 + x
SO, according to question
25% of (30+x) + (20+x) = (30+x)
Or, (20+x) = (30+x) - (25% of (30+x))
Or, 20+x = (30+x) [ 1 -(]
Or, 20+x = (30+x) (
Or, 80+4x = 90+3x
or 4x - 3x = 90-80
Or, x = 10
Hence the number of Non-Red pencils in the box which added further = 10 Answer