Answer:
6
Step-by-step explanation:
Cost per item is found by dividing the cost by the number of items. If the woman bought n items for $120, the cost of each item is $120/n. If the woman bought 24 more items, n+24, at the same price, then the cost per item is $120/(n+24). The problem statement tells us this last cost is $16 less than the first cost:
120/(n+24) = (120/n) -16
Multiplying by n(n+24) gives ...
120n = 120(n+24) -16(n)(n+24)
0 = 120·24 -16n^2 -16·24n . . . . . . subtract 120n and collect terms
n^2 +24n -180 = 0 . . . . . . . . . . . . . divide by -16 to make the numbers smaller
(n +30)(n -6) = 0 . . . . . . . . . . . . . . factor the quadratic
The solutions to this are the values of n that make the factors zero: n = -30, n = 6. The negative value of n has no meaning in this context, so n=6 is the solution to the equation.
The woman bought 6 items.
_____
Check
When the woman bought 6 items for $120, she paid $120/6 = $20 for each of them. If she bought 6+24 = 30 items for the same money, she would pay $120/30 = $4 for each item. That amount, $4, is $16 less than the $20 she paid for each item.
The answer would be A 4.2x3.7
Answer:
36.36% probability that she gave birth to quadruplets
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcoes.
Desired outcomes:
Giving births to quadruplets.
She has 4 sets of quadruplets.
So 
Total outcomes:
At least 3 children(triplets).
7 sets of triplets and 4 sets of quadruplets.
So 
Probability:

36.36% probability that she gave birth to quadruplets
Answer:
The mean length of the 13 people's big finger is 15.45 cm
Step-by-step explanation:
Given;
mean length of 4 childrens' big finger, x' = 14cm
mean length of 9 adults' big finger is 16.1cm, x'' = 16.1cm
Let the total length of the 4 childrens' big finger = t

Let the total length of the 9 adults' big finger = T

The total length of the 13 people's big finger = t + T
= 56 + 144.9
=200.9 cm
The mean length of these 13 people's big finger;
x''' = (200.9) / 13
x''' = 15.4539 cm
x''' = 15.45 cm (2 DP)
Therefore, the mean length of the 13 people's big finger is 15.45 cm
1/36 because there are 6 sides and the you are trying to figure out what the probiblity of rolling 1 out of 6 is