Answer:
The answer is, 2.5
Step-by-step explanation:
Multiply each pairs:
25%*10=250
Since Adding sugar mean that its concentration is 100%.
100%*x=100x
All of that equals to 40(10+x)
so, the equation is,
250+100x=400+40x
Do the equation and you are left with 2.5 as an answer.