Answer:
<h2>p(obtaining a red counter) = 0.625</h2>
Step-by-step explanation:
The total number of counters in the bag is 5 + 3 = 8.
and only 5 are red.
Then
the probability of obtaining a red counter is :

Answer:
the first term is a1
the distance between the numbers is d
we have:
a5 = a1 + 4d = 23
a12 = a1 + 11d = 72
so we have the equation:
a1 + 4d = 23
a1 + 11d = 72
=> a1 = -5
d = 7
=> an = -5 + 7(n - 1) = 7n - 12
with an = 7n - 12
=> a2 = 2
a3 = 9
so the first three terms is -5; 2; 9
The triangle: 4*4/2=8
The square: 4²=16
16+8=24
Factors of 15 - 1, 3, 5, 15
Factors of 18 - 1, 2, 3, 6, 9, 18
Factors of 30 - 1, 2, 3, 5, 6, 10, 15, 30
Your answer is D
Hope I helped you :-)