Answer:
<em>Cathy was born in 1980 and she was 18 years old in 1998</em>
Step-by-step explanation:
<u>Equations</u>
This is a special type of equations where all the unknowns must be integers and limited to a range [0,9] because they are the digits of a number.
Let's say Cathy was born in the year x formed by the ordered digits abcd. A number expressed by its digits can be calculated as
In 1998, Cathy's age was
And it must be equal to the sum of the four digits
Rearranging
We are sure a=1, b=9 because Cathy's age is limited to having been born in the same century and millennium. Thus
Operating
If now we try some values for c we notice there is only one possible valid combination, since c and d must be integers in the range [0,9]
c=8, d=0
Thus, Cathy was born in 1980 and she was 18 years old in 1998. Note that 1+9+8+0=18
260/32.5 = 8.
If 32.5 miles is equivalent to 1 gallon of gas, 260 miles is equivalent to 8 gallons of gas.
(32.5*8 = 260)
Answer:
246.137
Step-by-step explanation:
246.13687 ≈ 246.137 (rounded to the nearest thousandth)
Answer:
300 degrees
Step-by-step explanation:
pi should be 180 degrees so 5*180/3 = 5*60=300
35 Percent of 70 is 24.5
We assume, that the number 70 is 100% - because it's the output value of the task. We assume, that x is the value we are looking for. If 70 is 100%, so we can write it down as 70=100%. We know, that x is 35% of the output value, so we can write it down as x=35%. <span>Now we have two simple equations: 1.)70=100% 2.)x=35%</span>where left sides of both of them have the same units, and both right sides have the same units, so we can do something like that: 70/x=100%/35% Now we just have to solve the simple equation, and we will get the solution we are looking for.
