When ever you have percentages, it should be helpful to bear in mind you can express them as multipliers. In this case, it will be helpful.
So, if we let:
a = test score
b = target score
then, using the information given:
a = 1.1b + 1
a = 1.15b - 3
and we get simultaneous equations.
'1.1' and '1.15' are the multipliers that I got using the percentages. Multiplying a value by 1.1 is the equivalent of increasing the value by 10%. If you multiplied it by 0.1 (which is the same as dividing by 10), you would get just 10% of the value.
Back to the simultaneous equations, we can just solve them now:
There are a number of ways to do this but I will use my preferred method:
Rearrange to express in terms of b:
a = 1.1b + 1
then b = (a - 1)/1.1
a = 1.15b - 3
then b = (a + 3)/1.15
Since they are both equal to b, they are of the same value so we can set them equal to each other and solve for a:
(a - 1)/1.1 = (a + 3)/1.15
1.15 * (a - 1) = 1.1 * (a + 3)
1.15a - 1.15 = 1.1a + 3.3
0.05a = 4.45
a = 89
Multiples of 11 between 1 and 30:
11, 22
So there are 2 numbers that are multiples of 11 in the bin. There are a total of 30 cards, so the probability is written as 2/30. Or we can simplify it to 1/15.
For the next question:
There are a total of 3 + 8 = 11 balls in the bag.
The probability of choosing a red ball is 3/11.
The probability of choosing a green ball is 8/11.
Multiply the three fractions:
3/11 * 3/11 * 8/11 = 72/1331
So the probability is 72/1331.
For the last question:
A standard deck of cards has 52 cards.
There are 4 queens and 4 kings in the deck.
Probability of choosing a queen is 4/52, and the probability of choosing a king AFTER you already chose a queen is 4/51.
Multiply the two fractions:
4/52 * 4/51 = 16/2652
So the probability is 16/2652 or 4/663
Step 2 because what if they didn't think it was delicious....
Hello :)
The equation to volume of a rectangular prism is:
V=lwh
So, let's plug in the values and solve:
V=5×9.6×7
Answer: 336
Hope this helps and have a great day :D
I'm doing interval notations right now in pre-calculus, this how this notation should be written, (-∞,-2] or [4,∞), but this, (x ≤ -2] or [4 ≤ x), means the same thing. closed circle gets a bracket and an open circle gets a parenthesis, infinity always gets a parentheses because it is not a number. hope this helps
