9/27, 12/27, 16/27
So this is a geometric sequence as each term is 4/3 the previous term.
Since the common ration is greater than one the sum of the series diverges, it does not exist. (The sum just keeps getting larger and larger)
For a geometric series to have a sum r^2<1
So that the normal sum....
s(n)=a(1-r^n)/(1-r) becomes if r^2<1
s=a/(1-r)
T=time
d=st
r=train speed
p=plane speed
<span>160=rt
</span><span>720=pt
speed of plan is 20kmph less than 5 times speed of train
p=5r-20
we notice that 160 times 4.5=720
times first equaton by 4.5
720=4.5rt
720=pt
set equal
4.5rt=pt
divide both sides by t
4.5r=p
sub </span><span>p=5r-20 for p
4.5r=5r-20
minus 4.5r from both sides
0=0.5r-20
add 20 to both sides
20=0.5r
times 2 both sides
40=r
sub back</span><span>
p=5r-20
p=5(40)-20
p=200-20
p=180
plane is 180kmph
train is 40kmph
</span>
Answer:
184 boxes
Step-by-step explanation:
8648/47 = 184
