Percent formula : is/of = %/100
18 is what percent of 20...
is = 18
of = 20
% = x
sub and solve
18/20 = x/100
cross multiply
(20)(x) = (100)(18)
20x = 1800
x = 1800/20
x = 90 <=== so 18 is 90% of 20
Answer:
1356 cm²
Step-by-step explanation:
Each dimension gets multiplied by 2, so the new dimensions are
changed from 2x8x7 to 6x24x21
There are 6 faces to the prism,
The area of the front and back are 6x21 = 126. There are 2 of them for a total area of 126x2 = 252 cm²
The are of the left and right sides are 24x21 = 504. There are 2 of them for a total area of 504x2 = 1008 cm²
The area of the top and bottom are 6x24 = 144, there are 2 of them for a total area of 144x2 = 288 cm²
The total surface area is 252 + 1008 + 96 = 1356 cm²
Te difference of 2 standard deviation of a population n1 & n2 is given by the formula:
sigma (difference)=√(sigma1/n1 + sigma2/n2), Plug:
sigma(d)= √(49/100 + 36/50)
Sigma(d=difference) =1.1
She knits 18 squares on Monday.
Then she knits 7 more squares each day:
Tuesday: +7, Wednesday: +7, Thursday: +7 and Friday: +7
18 + 7 * 4 = 18 + 28 = 46
Answer: She has 46 squares on Friday.
