With 36 g of copper. 2. A swimming pool is filled in 30 hours by two identica pumps. How much quicker would it be filled if five similar pumps were used instead?

Let's break down the problem step by step. ### Known Conditions: 1. Two identical pumps fill a swimming pool in 30 hours. 2. We need to find out how much quicker the pool would be filled if five similar pumps were used. ### Step 1: Calculate the rate of one pump If two pumps can fill the pool in 30 hours, the rate of the two pumps together is: \[ \text{Rate of 2 pumps} = \frac{1 \text{ pool}}{30 \text{ hours}} = \frac{1}{30} \text{ pools per hour} \] To find the rate of one pump, we divide this rate by 2: \[ \text{Rate of 1 pump} = \frac{1}{30} \div 2 = \frac{1}{60} \text{ pools per hour} \] ### Step 2: Calculate the rate of five pumps Now, if we have five pumps, their combined rate would be: \[ \text{Rate of 5 pumps} = 5 \times \frac{1}{60} = \frac{5}{60} = \frac{1}{12} \text{ pools per hour} \] ### Step 3: Calculate the time taken by five pumps to fill the pool To find out how long it takes for five pumps to fill the pool, we take the reciprocal of their rate: \[ \text{Time taken by 5 pumps} = \frac{1 \text{ pool}}{\frac{1}{12} \text{ pools per hour}} = 12 \text{ hours} \] ### Step 4: Calculate the difference in time Now, we can find out how much quicker it is to fill the pool with five pumps compared to two pumps: \[ \text{Time difference} = 30 \text{ hours} - 12 \text{ hours} = 18 \text{ hours} \] ### Final Answer Using five pumps would fill the swimming pool **18 hours quicker** than using two pumps.