Answer: 
Step-by-step explanation:
Let be "x" the time in minutes a 150-pound person must walk at 4 mph to use at least 190 calories.
The amount of calories that a 150-pound person uses in 1 minute when walking at a speed of 4 mph is:

Therefore, knowing this, we can write the following proportion:

Finally, we must solve for "x" in order to find its value.
Multiplying both sides of the equation by 190, we get this result:

Answer:
B
Step-by-step explanation:
The ratio of the larger figure to the smaller figure is simplfying 30/12 to 5/2
Honest the 7/4 is just an educated guess because...yeah
Explanation
We are asked to give a counter-example for the given statement
A counter-example is an example that opposes or contradicts an idea or statement.
Therefore, for the statement
we have that
Statement: If an appliance is used for cooling
Conclusion: then it is a refrigerator
Then, the option that contradicts this, will be a clothes dryer
Because a dryer doesn't cool
Hence, the answer is a cloth dryer
option D
Answer: LAST OPTION.
Step-by-step explanation:
1. You have the following equation:

2. Then you must solve for x, as following:

Therefore, as you can see above, the answer for the exercise is the last option.
Answer:
2.4×10^6
Step-by-step explanation:
Put the numbers where the variables are and do the arithmetic. You can enter the numbers in scientific notation into your (scientific) calculator and have it show you the result in the same format.
r = (3.8×10^5)^2/(5.9×10^4) . . . . . denominator parentheses are required
Please note that in the above expression, parentheses are required around the denominator number. This is because it is a product of two numbers. In your pocket calculator or spreadsheet, you can enter that value as a single number (not a product). Parentheses are not required when you can do that.
r = (3.8²/5.9)×10^(5·2-4) ≈ 2.4×10^6
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The "exact" value is a repeating decimal with a long repeat. We have rounded to 2 significant digits here because the input numbers have that number of significant digits.