Question

Difficulty: MediumFractions and Decimals

A specialized aerospace component is manufactured from a custom metal alloy weighing exactly 160160 kg. The alloy's composition by weight is 0.350.35 aluminum and 516\frac{5}{16} magnesium, with the remaining portion consisting entirely of titanium. What is the exact mass of titanium in this component?

Answer: 54 kg

Answer

54
To find the mass of titanium, the total proportions of the other metals must first be unified into a common format (either fractions or decimals). By converting the magnesium's share of 516\frac{5}{16} to the decimal 0.31250.3125, the combined proportion of aluminum and magnesium is 0.35+0.3125=0.66250.35 + 0.3125 = 0.6625. The titanium makes up the remaining portion of the whole, which is 10.6625=0.33751 - 0.6625 = 0.3375. Finally, multiplying this decimal proportion by the total alloy mass of 160160 kg yields exactly 5454 kg.

Step-by-Step Solution

1
Convert the fractional part to a decimal.
516=0.3125\frac{5}{16} = 0.3125
Unifying the terms into a single format (decimals) makes addition straightforward.
2
Add the portions of aluminum and magnesium.
0.35+0.3125=0.66250.35 + 0.3125 = 0.6625
This finds the total proportion of the alloy that is NOT titanium.
3
Calculate the proportion of titanium.
10.6625=0.33751 - 0.6625 = 0.3375
The sum of all material proportions in the whole alloy must equal exactly 11.
4
Calculate the final mass of titanium.
0.3375×160=540.3375 \times 160 = 54
Multiplying the component's proportion by the total mass gives the specific weight of that component.

Key Concept

Converting between fractions and decimals and applying proportional reasoning to find a part of a whole.
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