Constant Rate Problems - Pre Algebra

1. How long does it take to travel $240$ kilometers at $60$ kilometers per hour?

   $4$ hours. Compute $240 \div 60$.

2. A pump moves $8$ gallons per minute. How many gallons does it move in $1$ hour?

   $480$ gallons. Compute $8 \times 60$.

3. A car travels $150$ miles in $3$ hours at a constant speed. What is its speed?

   $50$ miles per hour. Compute $150 \div 3$.

4. A faucet flows at $2.5$ liters per minute. How much water flows in $6$ minutes?

   $15$ liters. Compute $2.5 \times 6$.

5. What formula relates distance, rate and time at a constant speed?

   $d = rt$: distance equals rate times time.

6. A material has a density of $2$ grams per cubic centimeter. What is the mass of $15$ cubic centimeters?

   $30$ grams. Compute $2 \times 15$.

7. An object has a mass of $60$ grams and a volume of $20$ cubic centimeters. What is its density?

   $3$ grams per cubic centimeter. Compute $60 \div 20$.

8. A car travels at $45$ miles per hour for $4$ hours. How far does it go?

   $180$ miles. Compute $45 \times 4$.

9. A person walks $3$ miles in $45$ minutes at a constant pace. What is the speed in miles per hour?

   $4$ miles per hour. $45$ minutes is $\frac{3}{4}$ hour, and $3 \div \frac{3}{4} = 4$.

10. What formula gives density?

    Density equals mass divided by volume: $D = \frac{m}{V}$.

11. A printer prints $12$ pages per minute. How long does it take to print $90$ pages?

    $7.5$ minutes. Compute $90 \div 12$.

12. A cyclist rides $18$ miles in $1.5$ hours at a constant speed. What is the speed?

    $12$ miles per hour. Compute $18 \div 1.5$.

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