Question 1115859
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<pre>
Let x = 1st chemical amount (in kilograms);

    y = 2nd chemical amount;

    z = 3rd chemical amount.


From the condition, we have


x + y + z = 700                  (1)

x + y     = 490                  (2)    (70% of 700 kg)

    {{{y/z}}} = {{{4/3}}},    or   3y = 4z.     (3)


Subtract eq(2) from eq(1). You will get

    z = 700 - 490 = 210 kg.


Then from (3),  y = {{{(4*210)/3}}} = 280.



Then from (1),  x = 700 - 280 - 210 = 210.
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Solved.