Answer:
<em>The cost of 10 cm and 70 cm are £0.55 and £3.85 respectively.</em>
Step-by-step explanation:
Material for a dress costs £5.50 per meter.
We know that, <u>1 meter = 100 cm</u>.
Suppose, the cost of 10 cm material is
and the cost of 70 cm material is 
Now, <u>according to the ratio of "cost" to the "length of material"</u> , we will get.......

and

So, the cost of 10 cm material is £0.55 and the cost of 70 cm material is £3.85
Using binomial distribution where success is the appearing of any of the top 10 most common names, thus probability of success (p) is 9.6% = 0.096 and the probability of failure = 1 - 0.096 = 0.904. Number of trials is 11.
Binomial distribution probability is given by P(x) = nCx (p)^x (q)^(n - x)
Probability that none of the top 10 most common names appears is P(0) = 11C0 (0.096)^0 (0.904)^(11 - 0) = (0.904)^11 = 0.3295
Thus, the probability that at least one of the 10 most common names appear is 1 - 0.3295 = 0.6705
Therefore, I will be supprised that none of the names of the authors were among the 10 most common names given that the probability that at least one of the names appear is 67%.
25.8 that's what I got hope I could help