X and Y are two alloys of copper and aluminium prepared by mixing the metals in the ratio 6 : 5 and 5 : 9, respectively. If equal quantities of the alloys are melted to form a third alloy Z, what ratio of copper and aluminium will be in Z?
Answer & explanation
Correct answer: option 4
Cu : Al
X 6 : 5
Y 5 : 9
When equal quantity of both mixtures is mixed together
Cu : Al Total
X ( 6 : 5 = 11 ) x 14
Y ( 5 : 9 = 14 ) x 11
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X 84 : 70
Y 55 : 99
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139 : 169
The ratio of copper and alumininum in alloy Z is
139 : 169