Question

what are possible speeds for the jaggerblock to go? check all the answers that have the right type of units.
7.08 seconds/inch
500 inches per hour
900 miles
85 seconds/foot
894 seconds
what are possible relationships between nurses and doctors? check all the answers that have the right type of units
0.0053 nurses/second
0.252 doctors/nurse
110 doctors
10 nurses
4 nurses per doctor
what are possible rates for a person to lose weight on a new diet? check all the answers that have the right type of units.
160 pounds
0.0025 years
11 minutes per pound
670 seconds per pound
0.005 pounds/hour

Explanation:

Step1: Identify speed units

Speed is distance per time. Valid units have distance/time or time/distance.

• 7.08 seconds/inch: time/distance (valid)
• 500 inches per hour: distance/time (valid)
• 900 miles: only distance (invalid)
• 85 seconds/foot: time/distance (valid)
• 894 seconds: only time (invalid)

Step2: Identify nurse-doctor ratio units

Relationship is a count ratio. Valid units have count/count.

• 0.0053 nurses/second: count/time (invalid)
• 0.252 doctors/nurse: count/count (valid)
• 110 doctors: only count (invalid)
• 10 nurses: only count (invalid)
• 4 nurses per doctor: count/count (valid)

Step3: Identify weight loss rate units

Rate is mass per time or time per mass. Valid units have mass/time or time/mass.

• 160 pounds: only mass (invalid)
• 0.0025 years: only time (invalid)
• 11 minutes per pound: time/mass (valid)
• 670 seconds per pound: time/mass (valid)
• 0.005 pounds/hour: mass/time (valid)

Answer:

Possible speeds for the jaggerblock:

7.08 seconds/inch, 500 inches per hour, 85 seconds/foot

Possible relationships between nurses and doctors:

0.252 doctors/nurse, 4 nurses per doctor

Possible rates for weight loss:

11 minutes per pound, 670 seconds per pound, 0.005 pounds/hour