Call (F) the age of the father and (J) the age of Julio
The F & J are related in this way: F=4J
Now you have a restriction in the form of inequality: The sum of both ages has to be greater or equal than 55.
Algebraically that is: F + J ≥ 55
You can substitute F with 4J to find the solution for J:
4J + J ≥ 55
5J ≥ 55
Now divide both sides by 5
5J/5 ≥ 55/5
J ≥ 11
That Imposes a lower boundary for the value of J of 11, meaning that the youngest age of Julio can be 11
So volue of a cone=1/3 times (area of base[which is a circle]) times height
area of base=area of circle=pi time radius^2
area=pi times 5^2
area=pi times 25=25pi
1/3 times 25pi times 18
25pi times 18 times 1/3
25pi times 18/3
25pi times 6=150pi
the answer is 150π in^3 or 150π cubic inches or C
( to solve, aprox pi to 3.141592 an multiply 150 by 3.141592=471.239 in^3)
Since 1 km = 1000 m, the lawnmowers top speed would be 8000 m/h.
