The probability of one head and one tail is 2/3.
<u>Step-by-step explanation</u>:
- The possibilities for flipping two fair coins are {T,T}, {H,H}, {H,T}, {T,H}
- Given the case that at least one coin lands on a head, So the total possibilities are {H,H}, {H,T}, {T,H} = 3 possibilities
- Required event is 1 head and 1 tail= {H,T}, {T,H} = 2 possibilities
To calculate the probability of one head and one tail,
Probability = required events / Total events
Probability = 2/3
Copper: Nickel = 4:1
a) How much copper needed for 20 kg nickel
C:N = 4: 1
C:20 = 4:1
C/20 = 4/1 Cross Multiply
C*1 = 4*20
C = 80
80kg Copper would be needed.
b) How much Nickel would be needed for 20 kg of Copper
C:N = 4: 1
20:N = 4:1
20/N = 4/1 Cross Multiply
4*N = 1*20
4N = 20 Divide both sides by N.
N = 20/4 = 5
5kg Nickel would be needed.
27 multiplied by 10 will give you the answer. 27 x 10 = 270.