Answer:
The value of x would be
or 
Step-by-step explanation:
Given,
x tons of 10% gravel G mixture is mixed with y ton of 2% gravel G to obtain 5% gravel mixture,
Thus, gravel G in x ton + gravel in y ton = gravel G in the resultant mixture,
⇒ 0.1x + 0.02y = 0.05(x+y),
0.1x - 0.05x = 0.05y - 0.02y
0.05x = 0.03y

Now, resultant mixture is z ton,
i.e. 

From equation (1),




The constant rate = 20 ft / 5 seconds = 4 feet per second
Find the chart that shows an increase of 4 feet for every second the balloon travels.
14$ i think and good luck on ur test
21 is greater cause it whole number