ATI TEAS (Test of Essential Academic Skills) Version 7MathematicsHard
A research study involves participants from three age groups: Group A (20-30 years), Group B (31-40 years), and Group C (41-50 years). The number of participants in these groups are in the ratio 3:5:2, respectively. If there are 150 participants in Group B, what is the total number of participants in the study?
- A300
- B350
- C400
- D250
Show answer & explanationAnswer & explanation
Correct answer: A. 300
The ratio is 3:5:2, meaning for every 3 parts in Group A, there are 5 parts in Group B, and 2 parts in Group C. The total parts are 3 + 5 + 2 = 10 parts. If 5 parts (Group B) equal 150 participants, then one part is 150 / 5 = 30 participants. The total number of participants is 10 parts * 30 participants/part = 300 participants.
Why the other options are wrong
- B. This indicates an error in determining the value of one part or the total parts.
- C. This could be a miscalculation or an incorrect setup of the proportion.
- D. This might result from incorrectly calculating the value of one part or adding the ratio parts.
Ratio to Total Quantity
Using a given ratio and the actual quantity of one part to determine the total quantity of all parts combined.
- Sum the ratio parts to find the total number of 'units' in the ratio.
- Use the known quantity for one part of the ratio to find the value of one 'unit'.
- Multiply the total ratio units by the value of one unit to get the total quantity.
Memory trick: Ratio parts sum, find one part's worth, then multiply for the sum.