X + y is the number of students who were surveyed.
x is the number who own a bike.
y is the number who don't.
the ratio of the ones who own a bike and the ones who were surveyed is x / (x + y)
that ratio is 7/8.
you get x / (x + y) = 7/8
multiply both sides of this equation by (x + y) to get x = (x + y) * 7/8
simplify to get x = 7/8 * x + 7/8 * y
subtract 7/8 * x from both sides of this equation to get:
1/8 * x = 7/8 * y
solve for x to get x = 7 * y
this means that the number of students who own a bike is 7 times the number of students who don't.
divide both sides of that equation by y to get x/y = 7/1.
that means that the ratio of students who own a bike to the number of students who don't is equal to 7/1.
the problem states that the difference between the number who own a bike and the number who don't is 72.
this means that x - y = 72
from the equation of x = 7 * y, replace x with 7 * y in the equation of x - y = 72 to get:
7 * y - y = 72
simplify to get 6 * y = 72
divide both sides of that equation by 6 to get y = 72/6 = 12
this means that the number of students who do not own a bike is 12.
since x = 7 * y, then x = 7 * 12 = 84.
this means that the number of students who own a bike is 84.
since the number of students is x + y, this means that the number of students who were surveyed is 84 + 12 = 96.
let's see if this is right.
96 students were surveyed.
84 own a bike and 12 don't.
the difference between the ones who own a bike and the ones who don't is 84 - 12 = 72.
the ratio of the ones who own a bike and the number surveyed is 84/96 = 7/8.
solution is 96 students were surveyed.
The answer is -1.5+(-2.75)=-4.25. This equation is the same as the result of -1.5 -2.75.
Answer:
3 x 3 = 9
Step-by-step explanation:
Each spin consists in a choice of a number among 1, 3, 4 and 6. This means that there are two odd numbers and two even numbers.
You get an even number if you sum two numbers with the same parity, you get an odd number if you sum two numbers with opposite parity.
Whatever number you get from the first spin, you have a 50% chance of spinning a number with the same parity with the second spin, and a 50% chance of spinning a number with opposite parity with the second spin.
So, with each turn, you have a 50% chance of getting an even sum, and a 50% chance of getting an odd sum.
This means that, by definition, the expected number of spaces moved is
So, on average, you move 2 steps foward.
Answer:
second one
Step-by-step explanation:
Notice that there's a y intercept of 2 and an x intercept of -4
This means that the line has a positive slope of 1/2, which leaves us with
y<(1/2)x+2
