Answer for #1
Let the old price be
$
x
per liter. 10 liters would have cost a total of
$
10
x
.
The new price is
$
(
x
+
0.20
)
per liter. 10 liters would have cost
$
10
(
x
+
0.20
)
.
The total cost is
$
9.20
. So,
10
x
+
10
(
x
+
0.20
)
=
9.20
10
x
+
10
x
=
9.20
−
2
x
=
7.20
20
x
=
0.36
Thus, the old price was
$
0.36
per liter.
Answer:
2^n
Step-by-step explanation:
So whenever you flip a coin, you can see it as 2 nodes branching off of each existing node. so for example when you flip a coin once you're going to have 2 sequences initially H and T, now when you flip a coin again for each of those 2 sequences 2 are going to branch off of that, making the total sequences 4, and the next flip 2 sequences are going to branch off each of the 4 sequences and so on. this can generally be described as: 2^n
I attached an image describing this a bit better but the bottom line is that for each 'end node'/sequence you're going to have 2 branch off of it, thus for each coin flip the number of sequences multiplies by 2
Six less than five times a number is at least 29.