Answer:
<em>Trabajó 3 horas al día</em>
Step-by-step explanation:
<u>Proporcionalidad</u>
Una persona planeó terminar la obra en 15 dias, pero tardó 10 dias adicionales porque trabajó 2 horas menos por día.
Usaremos proporciones para calcular las horas de trabajo diarias.
Si 2 horas diarias representan 10 dias de atraso, entonces cada hora representa 5 dias de trabajo.
Si la obra tardaba 15 dias, entonces la persona trabajó 15/5 = 3 horas diarias.
Answer:
Radius, r, is 3.75
Step-by-step explanation:
From the given diagram,
AB = 9
AC = 6 + r
BC = r
Thus applying the Pythagoras theorem, we have;
=
+ 
=
+ 
36 + 12r +
= 81 + 
collecting like terms,
12r = 81 - 36
12r = 45
r = 
= 3.75
r = 3.75
The radius is 3.75.
Answer:
<h2>B. The amount of fuel used was lowest at speeds around 60km/h.</h2>
Step-by-step explanation:
The decreasing part is from (20,13) to (60,6), which gives an average rate of

Then, we have an increasing part from (60,6) to (120,10), which gives an average rate of

Basically, at 60 km/h the fuel used was 6 liters per 100 kilometers. Notice that the other velocities make the car to use more liters per kilometers.
Therefore, the amount of fuel used was lowest at speeds around 60 km/h.