First, we inspect what type of sequence is the order of the coordinates:
a2 = 1
a3 = 2
a4 = 4
Getting the difference,
a3 - a2 = 1
a4 - a3 = 2
The differences are not equal; hence, the sequence is not arithmetic.
Getting the ratio:
a3/a2 = 2
a4/a3 = 2
The common ratio is 2. Using the general form for a geometric series:
an = a1 r^(n-1)
If n = 2
1 = a1 (2)^(2-1)
a1 = 1/2
So,
an = (1/2) (2)^(n-1)
The answer is the first option.
Answer:
C) 15
Step-by-step explanation:
Here we have to use the combination to find the number of possible combinations.
Total number of classmates (n) = 6
We are selecting 2 individuals. So r = 2.
The combination formula nCr = 
Plug in n = 6 and r =2, in the above formula, we get
= 
= 
Simplifying the above factorial, we get
= 15
So the answer is C) 15
9 I think because 1/4 needs to have 4 of those to be a whole so yeah 9.
2km=2 kilometer
kilo=1000 so 2 km=2000m
25m
2500cm
cm=centimeter=1/100 of a meter
so
2500cm=25m
mm=milimeter=1/1000 meter
so
3000mm=3m
so the longets is obviously 2000m or 2km
Answer: 5040 7-digit numbers
Step-by-step explanation:
Permutations:
1: 1 ==> 1 permutation ==> 1 ==> 1!
12: 12, 21 ==> 2 permutations ==> 1*2 ==> 2!
123: 123, 132, 213, 231, 312, 321 ==> 6 permutations ==> 1*2*3 ==> 3!
7-digits: 7!=
1*2*3*4*5*6*7=5040 7-digit numbers
