How to translate word sentence into algebra expression and write one variable equation?

Question:

A store received 3000 bags of flour on the first day, 25% of which is unbleached flour. The next day another batch of unbleached flour arrived. At this time unbleached flour account for two-thirds of the total flour. How many bags of unbleached flour were arrived on the next day?

Solution:

Let x be the unbleached flour arrived on the next day.

First day unbleached flour = 25% × 3000

Next day unbleached flour = x

Total unbleached flour = x + 25% × 3000

Total flour = 3000 + x

The relationship is: total unbleached flour is equal to two-thirds of the total flour.

x + 25% × 3000 = (2/3) (3000 + x)

x + 750 = (2/3) (3000) + (2/3) x

x - (2/3) x = 2000 - 750

(1/3) x = 1250

x = 3 × 1250 = 3750

There are 3750 bags of unbleached flour were shipped to the store on next day.