If we assume that
x isthe number of multiple choice questions, and y is the number of word problems, we can write a system of equations like:
{ x + y = 38
{ 2x + 5y = 100
If we multiply the first equation by -2 we get:
{ -2x-2y = -76
{ 2x + 5y = 100
Now if we add both equations we get only equation with 1 unknown (y) :
3y = 24 ⇒ y = 8
Substituting the calculated value to the first equation we get:
x + 8 = 38 ⇒ x = 30
The solution:
{ x = 30
{ y = 8
means that:
The test had 30 multiple choice questions, and 8 word problems.
This isn't a math question and should be in the science section. However, I will still answer the question. The answer is choice B.
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Here's a further breakdown
A. False. The radiation or energy from the sun can travel through air or else you wouldn't feel the sun's rays. Also, plant life wouldn't be alive without that energy going through the air.
B. True. The rays travel through a vacuum of space. If they couldn't travel through space, then the same problem comes up as in choice A: the issue of not feeling the sun's rays.
C. False. They rays have different frequencies. Because there are many wavelengths (see choice D below), this means there are different frequencies. Recall that f = 1/w where f is the frequency and w is the wavelength.
D. False. The rays are made of different wavelengths. The visible light portion is what we can see, though there is a lot more to the electromagnetic spectrum (eg: ultraviolet light).
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So once again, the answer is choice B
Answer:
the point
Step-by-step explanation:
the point makes a decimal a decimal
