Answer:
(a) PC(C)= 
(b) E[C] = 24 cents
Step-by-step explanation:
Given:
Cost to receive a photo = 20 cents
Cost to send a photo = 30 cents
Probability of receiving a photo = 0.6
Probability of sending a photo = 0.4
We need to find
(a) PC(c)
(b) E[C]
Solution:
(a)
PC(C)= 
(b)
Expected value can be calculated by multiplying probability with cost.
E[C] = Probability × cost
E[C] = 
To find the answer, you should divide 405 by 50 to find the mass of one coin. The formula should look like this:

= 8.1
The exact mass is 8.1 grams, but because you want an estimate, the answer should be
About 8 grams for the mass of 1 one-dollar coin
Before we could add these numbers, 3/8 and 7/10 need a common denominator. Both 8 and 10 go into 40.
8 goes into 40 five times
3/8= (3*5)/40 = 15/40
10 goes into 40 four times
7/10= (7*4)/40= 28/40
ANSWER: A) 15/40 and 28/40
Hope this helps! :)
Area of parallelogram = base * height
base 1 = 4.2 cm
height 1 = 3.6 cm
∴ Area = 4.2 * 3.6 = 15.12
let the other base 2 = x
∴ the altitude of this base = height 2 = 2.4
∴Area = 2.4 x = 15.12
Solve for x
∴ x = 6.3 cm
∴ The perimeter of parallelogram = 2( base 1 + base 2)
= 2 ( 4.2 + 6.3 ) = 21 cm