Answer:
Probability of selecting one volcano in the world on which to conduct an extensive study is given by

Step-by-step explanation:
Since we have given that
Number of cinder cone volcanoes = 13
Number of shield volcanoes = 18
Number of strato volcanoes = 6
Total number of volcanoes is given by

So, Probability of getting one volcano in the world on which to conduct an extensive study is given by

Hence, Probability of selecting one volcano in the world on which to conduct an extensive study is given by

Answer: the old price for 1 liter is $0.3
Step-by-step explanation:
Let x represent the old price for 1 liter of petrol.
Last week a man bought 20 liters at the old price. This means that the total amount that the man paid for 20 liters is 20x.
The cost of petrol rises by 2 cents a liter. This means that the new price per liter is x + 2/100 = x + 0.02
This week he bought 10 liters at the new price. This means that the total amount that the man paid for 10 liters is
10(x + 0.02)
= 10x + 0.2
Altogether, the petrol costs $9.20. This means that
20x + 10x + 0.2 = 9.2
30x + 0.2 = 9.2
30x = 9.2 - 0.2
30x = 9
x = 9/30
x = 0.3
Step-by-step explanation:
Since B is the midpoint of AC. So,
AB = BC
12x - 12 = 4x + 28
12x - 4x = 28 + 12
8x = 40
x = 40/8
x = 5
Now,
AB = BC = 4(5) + 28
= 20 + 28
= 48 cm
Now
AC = AB + BC
AC = 48 + 48
AC = 96 cm