Answer:
x = 87.5
Explanation:
0.4x + 10 = 45
Subtract 10 from both sides
0.4x + 10 − 10 = 45 − 10
0.4x = 35
Divide both sides by 0.4
0.4x / 0.4 = 35 / 0.4
x = 87.5
I assume you want to know a permutation about how many ways they can be in the final set-up.
Order matters, which is why this is a permutation.
Formula: P(n, r) =

where the permutation is

, with P for permutation.
Plug in:
4!/(4-2)!
4!/2!
(1 x 2 x 3 x 4)/1 x 2
(3x4)/1
= 12
12 ways.
If the amount she saved was $6 for 20%, then the formula for finding savings would be cost*percentage.
But if you want to find the original cost, then you play with the current formula until you get this. $6/20%. Have a good one :)
Answer:
Justin is correct
Step-by-step explanation: Chris's mistake was he probably didn't know that 1 kg = roughly 2.2 pounds