Answer:
B - The surface area is multiplied by 4.
Step-by-step explanation:
The first step is to figure out the original surface area of the shape using this formula;
<em>A = 2(wl + hl + hw)</em>
Which in this problem, means:
<em>A = 2 (5 × 9) + 2 (3 × 9) + 2 (3 × 5) = 174.</em>
Now, we must figure out the surface area once the measurements are doubled, using the same equation:
<em>A = 2 (10 × 18) + 2 (6 × 18) + 2 (6 × 10) = 696.</em>
If we then take a look back at the original surface area, we can already tell the answer is not D, as 696 is too high to be double 174, considering 150 × 2 is 300, and 24 × 2 is 28.
We can also eliminate option A, as it's clear multiplying 174 by 8 would take us into the thousands, since 8 × 100 is 800, and already over our target.
So we're left with two options - Multiplied by 4, or multiplied by 6.
If we know that multiplying 174 by 8 would take our answer into the thousands, it's also safe to assume multiplying by 6 would do the same, because 6 × 100 is 600, and multiplying 74 by 6 would take us way over target, too.
However, just to be on the safer side, we can divide 696 by 6;
<em>696 ÷ 6 = 116.</em>
Now we have eliminated answer C.
So the answer is B - The surface area is multiplied by 4.
(Confirmation -
<em>696 ÷ 4 = 174</em>
<em>174 × 4 = 696)</em>
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Hope this helped!</u></h2>
