Answer:
0.4 sec
Step-by-step explanation:
Remember that
1 mile=5,280 feet
1 foot=12 inches
1 hour=3,600 seconds
Let
s -----> the speed in ft/sec
d ----> the distance in ft
t -----> the time in sec
s=d/t
Solve for t
t=d/s
step 1
Convert miles/hour to ft/sec
105 mi/h=105(5,280/3,600)=154 ft/sec
Convert 60 ft 6 in to ft
60 ft 6 in=60+(6/12)=60.5 ft
step 2
Find the time
t=d/s
we have
s=154 ft/sec
d=60.5 ft
substitute
t=60.5/154
t=0.39 sec
Round to the nearest tenth
t=0.4 sec
Just solve the equation, x + 0.15x + 0.06x = 15
1.21x = 15,
x = $12.39 (nearly)
Answer: the answer is D = 210cm
-44.09 i dont understand why we must have 20 characters but OK
