Answer:
42.5 or 43
Step-by-step explanation:
Since you need to travel 850 miles, and you can travel 20 miles per gallon, you should divide 850 by 20 to get the number of gas cans needed. In doing so, you get 42.5 gas cans, but since it may be asking for whole cans rather than part of a gas can, you might want to write 43 instead. If you were to round down to 42, you would not have enough gas to finish the trip, so you should round up to 43. So, it is up to you if you want to write 42.5 or 43.
Hope this helped somewhat! ;(
All you gotta do is subtract both of the numbers to get how much you need.
93 - 75 = 18
We can double check to see if it's right by using addition
18 + 75 = 93
Sonny needs to borrow 18$ to meet his required amount :D
8.9
The equation for the grain size is expressed as the equality:
Nm(M/100)^2 = 2^(n-1)
where
Nm = number of grains per square inch at magnification M.
M = Magnification
n = ASTM grain size number
Let's solve for n, then substitute the known values and calculate.
Nm(M/100)^2 = 2^(n-1)
log(Nm(M/100)^2) = log(2^(n-1))
log(Nm) + 2*log(M/100) = (n-1) * log(2)
(log(Nm) + 2*log(M/100))/log(2) = n-1
(log(Nm) + 2*log(M/100))/log(2) + 1 = n
(log(33) + 2*log(270/100))/log(2) + 1 = n
(1.51851394 + 2*0.431363764)/0.301029996 + 1 = n
(1.51851394 + 0.862727528)/0.301029996 + 1 = n
2.381241468/0.301029996 + 1 = n
7.910312934 + 1 = n
8.910312934 = n
So the ASTM grain size number is 8.9
If you want to calculate the number of grains per square inch, you'd use the
same formula with M equal to 1. So:
Nm(M/100)^2 = 2^(n-1)
Nm(1/100)^2 = 2^(8.9-1)
Nm(1/10000) = 2^7.9
Nm(1/10000) = 238.8564458
Nm = 2388564.458
Or about 2,400,000 grains per square inch.
