Question 1122090
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The number of either yellow or black shirts is equal to


    {{{750 - (1/5)*750 - (1/10)*750}}} = 525.


Now, from the condition, you have these two equations


B + Y = 525,    (1)     (where B = #of black shirts;  Y = #of yellow shirts)

B - Y =  85     (2)


Add these two equations to get


2B = 525 + 85 = 610  ====>  B = 610/2 = 305.


Then from eq(1),  Y = 525 - 305 = 220.


<U>Answer</U>.  305 black shirts and  220 yellow shirts.
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