There are 20 students in a math class who have brown hair. This represents 80 percent of the students in the class. Which equation can be used to find the total number of students in the math class? 20 x 100 2000 80x 100 2000 E 400 80 x 5 20x5 90-4 100=4 25 20-120 80-180

The answer is C

Step-by-step explanation:

A. The probability that a person older  than 35 years has a hemoglobin

level less than 9 is 76/162 or 0.47 (rounding to two decimal places)

B. The probability that a person  younger than 25 years has a  hemoglobin level above 11 is 69/139 or 0.50 (rounding to two decimal places).

C. The probability that a person in the  25–35 age group has a hemoglobin  level less than 9 is 32/128 or 0.25.

D. The probability that a person older  than 35 years has a hemoglobin  level between 9 and 11 is 46/162 or 0.28 (rounding to two decimal places).

Step-by-step explanation:

1. Let's review the information given to solve these questions:

The people surveyed were grouped in three range of ages: less than 25 years , 25 to 35 years and over 35 years. Related to the hemoglobin level, the ranges were also three: less than 9, between 9 and 11 and above 11.

Total of persons surveyed = 429

Less than 25 surveyed = 139

Between 25 and 25 years old = 128

Older than 35 = 162

From the less than 25 surveyed people, 21 had hemoglobin less than 9, 49 between 9 and 11 and 69 had above 11 of hemoglobin level.

From the 25 to 35 surveyed people, 32 had hemoglobin less than 9, 52 between 9 and 11 and 44 had above 11 of hemoglobin level.

Finally, from the group of people above 35 years,  76 had hemoglobin less than 9, 46 between 9 and 11 and 40 had above 11 of hemoglobin level.

2. Now let's drag the tiles to the correct boxes to complete the pairs.

A. The probability that a person older  than 35 years has a hemoglobin

level less than 9 is 76/162 or 0.47 (rounding to two decimal places)

B. The probability that a person  younger than 25 years has a  hemoglobin level above 11 is 69/139 or 0.50 (rounding to two decimal places).

C. The probability that a person in the  25–35 age group has a hemoglobin  level less than 9 is 32/128 or 0.25.

D. The probability that a person older  than 35 years has a hemoglobin  level between 9 and 11 is 46/162 or 0.28 (rounding to two decimal places).