This problem is describe the mole-ratio composition of an allow composed by tin, lead and cadmium. Ratios are given as Sn:Pb 2.73:1.00 and Pb:Cd is 1.78:1.00, and we are asked to calculate the mass percent compositon of Pb in the allow.
In this case, according to the given information, it turns out possible realize that the following number of moles are present in the alloy, according to the aforementioned ratios:

Next, we calculate the masses by using each metal's atomic mass:

Thus, the mass percent composition of each metal is shown below:

So that of lead is 34.9 %.
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Answer: Environment
Explanation:
Organisms can be placed in an environment not like their own, but can learn to adapt by exploring and interacting with the new environment.
Answer:
E) All three samples have the same number of hydrogen atoms
Explanation:
The statements are:
A) Sample A has more hydrogen atoms than sample B or sample C.
B) Sample B has more hydrogen atoms than sample A or sample C.
C) Sample C has more hydrogen atoms than sample A or sample B
D) Both samples A and C have the same number of hydrogen atoms, but more than in sample B.
E) All three samples have the same number of hydrogen atoms
Hydrogens in sample A are:
180g × (1mol Glucose / 180.156g) × (12mol H / 1 mol Glucose) =<em> 12 moles of H</em>
Hydrogens in sample B are:
90g Glucose × (1mol Glucose / 180.156g) × (12mol H / 1 mol Glucose) =<em> 6 moles of H</em>
90g mannose× (1mol Mannose / 180.156g) × (12mol H / 1 mol Glucose) =<em> 6 moles of H</em>
<em>Total moles: 12</em>
Hydrogens in sample C are:
180g × (1mol Mannose / 180.156g) × (12mol H / 1 mol Glucose) =<em> 12 moles of H</em>
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Thus, right answer is:
<em>E) All three samples have the same number of hydrogen atoms</em>
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I hope it helps!