It is given in the question that
The gas tank of Tyrell's truck holds 19.8 gallons. when the tank empty, Tyrrell fills it with gas that costs $3.65 per gallon.
It means cost of one gallon of gas is $3.65 .
And the tank hold 19.8 gallon . So cost of 19.8 gallon is

Therefore about $72.27 it will cost to fill the tank .
Let the three numbers be x, y and z. Then x+y+z=75.
z = 2x. y = x - 9.
Eliminate y and z by substitution: x + (x - 9) + (2x) = 75
Then 4x = 75 + 9, or 4x = 84. x = 21, y = 21 - 9 = 12, and z = 2(21) = 42.
Check: Do 21, 12 and 42 add up to 75?
D is the answer for this problem
There are seven SI base
units which are used in science, every unit has its own property or use:
Meter (length)
Kilogram (mass)
Second (time)
Kelvin (temperature)
Mole (amount of substance)
Ampere (electrical unit) and
Candela (luminous intensity)
<span>The SI unit of
measure for length (meter) would be most appropriate when we are measuring the
distance between two places or when we are taking measurement of something.</span>
There are 1760 yards in a mile. Half that distance is 880 yards.