(10+15)*2=50 см кружева на одну салфетку
50*6=300 см=3 м на шесть салфеток
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A / B = 3 ---> A = 3B
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A + 5B + 22 = 3B + 5B + 22 = 8B + 22 = 2 * ( 4B + 11 )
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A + B + 11 = 3B + B + 11 = 4B + 11
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( 2 * ( 4B + 11 ) ) / ( 4B + 11 ) = 2m
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ОТВЕТ 2
1) 1/3% : 100% = 1/300
2) 5/7% : 100% = 5/700
3) 2 3/8% : 100% = 19/8% : 100% = 19/800
4) 5 2/9% : 100% = 47/9% : 100% = 47/900
5) 104 1/3% : 100% = 313/3% : 100% = 313/300