The equation would be 2n-7
Let the cost of the hair dryer equal x.
The net cost plus a 40% markup equals 42, set up an equation and solve forex.
1.4x = 42
Divide both sides by 1.4
X = 42 / 1.4
X = 30
The net cost was £30
Answer: There are 4 possibilities. They are all listed below with their percents.
You can create a tree diagram to shows all of the possibilities. It will start with 2 branches and then each of those branches will have 2 branches.
The possibilities are: UU, UD, DU, DD
To find the probabilities of each, you have to multiply the percent for each together.
UU = 0.66 x 0.66 = 0.4356
UD = 0.66 x 0.34 = 0.2244
DU = 0.34 x 0.66 = 0.2244
DD = 0.34 x 0.34 = 0.1156