[Video] Q15: C = 5/9 (f -32) the equation above shows how a temperature f, measured in degrees fahrenheit, relates to a temperature c, measured in degrees celsius. based on the equation, which of the following must be true? i. a temperature increase of 1 degree fahrenheit is equivalent to a temperature increase of5/9 degree celsius. ii. a temperature increase of 1 degree celsius is equivalent to a temperature increase of 1.8 degrees fahrenheit. iii. a temperature increase of 5/9 degree fahrenheit is equivalent to a temperature increase of 1 degree celsius.

Explanation for Question 15 From the Math (No Calc) Section on the Official Sat Practice Test 3

Now for number 15 where you given this equation, 2 right? Which those, the temperature in Fahrenheit, 3 um, as related to Celsius. And so our asked which of the following must 4 be true. So I want to emphasize that it says must, 5 right? So that means that whatever we say should always be true, 6 not just sometimes, um, in the best way to go about these is just 7 to look at each, uh, each statement and decide whether or not that would 8 be true. Um, and so if we look at one, 9 it says a temperature increase of one degree, 10 Fahrenheit is equal, is equivalent to a temperature increase of five over 11 six Celsius. Right? So let's go ahead and see what that 12 means. So as I increase every Fahrenheit 13 by one, I'm multiplying that by five over nine, 14 right? So essentially that is true, 15 right? Because each time I multiply or increase the Fahrenheit by one, 16 I multiply by five overnight in additional time. 17 For example, if I had a Fahrenheit temperature of 32, 18 then I would be at zero, right. My Celsius would be zero. 19 So let's start a chart here, Fahrenheit Celsius. 20 But if I have a Fahrenheit temperature of 33, 21 right, I do 33 minus 32 times five nights, 22 it's just five nights. 23 Right? And so in that case, the one degree increase in Fahrenheit led to 24 five nights, uh, increase in Celsius. 25 So one is true and I now just have to decide between a and 26 D. Um, so we'll look at two, 27 two says the temperature in degree, uh, increase of one degree, 28 Cels...