Answer:
Both castles will have the same height at 3.33 minutes
Step-by-step explanation:
This problem will be solved with linear modeling, that is, expressing both people's sand castle's height as a function of time.
Justin built a sandcastle 180 cm tall, and its height is losing at 8 cm/min by the effect of wind. Thus, the height of Justin's sandcastle is:
[tex]H_J=180-8t[/tex]
Where t is the time expressed in minutes.
Taylor's sandcastle is initially 160 cm tall. The wind blows away sand at 8 cm/min but she adds sand at 6 cm/min, thus the real loss of sand is 8 cm/min - 6 cm/min= 2 cm/min. Thus, the height of Taylor's sandcastle is:
[tex]H_T=160-2t[/tex]
To find when both castles have the same height, we set:
[tex]180-8t=160-2t[/tex]
Simplifying:
6t=20
Solving:
t=20/6=3.33\ minutes
Both castles will have the same height at 3.33 minutes
