90-20 leaves 70 for surfing. since surfing is 5 per hour, 70/5=14 hours she can surf.
Answer:
D
Step-by-step explanation:
The correct answer choice is D. Note how BC and MN appear to have nearly the same lengths, whereas none of the other statements are true. Note, also, that this diagram is not to scale; you could make the problem easier by redrawing MNOP so that it has the same orientation as does ABCD and the same corresponding side lengths.
Hello!
The number 49 is similar to other numbers like 25, 81, 4, or 64. All these numbers are perfect squares. Perfect squares are numbers multiplied by itself. Here is a list of commonly used perfect squares.
- 1 × 1 = 1
- 2 × 2 = 4
- 3 × 3 = 9
- 4 × 4 = 16
- 5 × 5 = 25
- 6 × 6 = 36
- 7 × 7 = 49
- 8 × 8 = 64
- 9 × 9 = 81
- 10 × 10 = 100
- 11 × 11 = 121
- 12 × 12 = 144
From the list above, the square root of 49 is 7, but the question asks for the <u>negative</u><u> square root of 49</u>, which is written as: -√49.
To simplify this expression, first, simplify the radical, and then multiply the product by negative one.
7 × -1 = -7
Therefore, the negative square root of 49 is choice C, - 7.
Since the bacteria is 10^-6 m long and the virus is 10^4 times smaller, the virus is (10^-6)/(10^4) m or 10^-10 m or 10 angstroms or 0.1 nanometers
