Answer:
8.75%
Step-by-step explanation:
If she pays $135 eight times then she pays a total of 135 x 8 = $1080.
She had a down payment of $225, so that added on becomes $1305.
1305/1200 is 1.0875, which is an increase of 0.0875 over the original.
0.0875 x 100 = 8.75% increase.
The three numbers are 52, 53, 54.
52+53=105 105+54=159
Y = 40 + 4m
m = minutes
y = total papers graded
Part A: each tricycle has three wheels, so with 48 wheels the number of tricycles was a =48/3=16 tricycles.
t=w/3 (the number of tricycles is the number of wheels divided by 3)
Part B:
The number of seats:
24=b+a (so b=24-a)
The number of seats is the sum of one seat per bicycle and one seat per a tricycle
also, 61=2a+3b (the number of wheels)
So we have:
24=b+a
b=24-a
We can substitute this for b:
61=2a+3(24-a)
and solve:
61=2a+3*24-3a
61=72-a
a=72-61
a=11
There were 11 bicycles!!
and there were 24-11 tricycles, so 13 tricycles.
Part C: each of the bikes has only one front-steering handlebar, so there were a total of 144 vehicles:
a+b+c=144
There were 378 pedals. And the number of pedals is:
2a+2b+4c=378 (the numbers 2,2,4 represent the number of pedals per vehicle)
divide by 2:
a+b+2c=189
Now, we have
a+b+2c=189
and
a+b+c=144
and we can subtract them from each other:
a+b+c-(a+b+2c)=144-189
-c=45
c=45, so there were 45 tandem bicycles!
(this also means that a+b=144-45, that is a+b=99)
now the wheels:
3a+2b+2c=320
Let's substitute c:
3a+2b+90=320
which is
3a+2b=240
We also know that a+b=99, so we can substract this from this equation:
3a+2b+-a-b=240-99
2a+b=141
and again:
2a+b-a-b=141-99
a=42 - there were 42 trycicles!!!
And the bicycles were the rest:
99-42=57 bycicles
