Sadie is 3 years older than Kareem, and Kareem is twice as old as Nadra. The sum of their ages is 33. A student used the steps below to find each person’s age.

Step 1 Write an equation, letting x represent Kareem’s age:
(x + 3) + x + 2 x = 33
Step 2 Solve the equation:
(x + 3) + x + 2 x = 33. 3 + 4 x = 33. 4 x = 30. x = 7 and one-half.
Step 3 Sadie is 10 and one-half, Kareem is 7 and one-half, and Nadra is 3 and three-fourths.

Which corrects the student’s first error?
In Step 1, the student should have used One-half x to represent Nadra’s age, and written the equation (x + 3) + x + one-half x = 33.
In Step 2, the student should have added 3 on both sides of the equation to find a solution of x = 9.
In Step 3, the solution represents Sadie’s age. Therefore, Sadie is 7 and one-half, Kareem is 4 and one-half, and Nadra is 2 and one-fourth.
In Step 3, Nadra’s age is the difference between 33 and Sadie’s and Kareem’s ages, so Nadra is 15.

The correct answer is:

In Step 1, the student should have used One-half x to represent Nadra’s age, and written the equation (x + 3) + x + one-half x = 33.

Step-by-step explanation:

Lets solve the problem step by step correctly

Let x be the age of Kareem

Let s be sadie's age

n be Nadra's age

According to "Sadie is 3 years older than Kareem"

And According to "Kareem is twice as old as Nadra"

x = 2n

n = x/2

Step 1: Writing the equation

Step 2: Solving the equation:

Step 3

Kareem's Age = 12

Sadie's Age = x+3 = 12+3 = 15

Nadra's Ade = 12/2 = 6

The student made the error in Step 1 where he wrote the equation.

Hence,

The correct answer is:

In Step 1, the student should have used One-half x to represent Nadra’s age, and written the equation (x + 3) + x + one-half x = 33.

85.560%

step-by-step explanation:

conditional probability is defined as:

p(a|b) = p(a∩b) / p(b)

in other words, the probability that a occurs, given that b has occurred = the probability that both a and b occur / the probability that b occurs.

in this example:

p(turns 64 | turns 44) = p(turns 64 & turns 44) / p(turns 44).

if someone turns 64, they must have already turned 44, so:

p(turns 64 | turns 44) = p(turns 64) / p(turns 44)

on page 42, we see that of the original 100,000, 94944 turn 44, and 81234 turn 64.   therefore:

p(turns 64 | turns 44) = 81234 / 94944

p(turns 64 | turns 44) = 0.85560

the answer is 21%.