Grades 9-10 Video Solutions 2023-2023_9-10

Video Transcription

Video Summary

Julia is trying to save water. She reduced the time she spent in the shower by a quarter. She also lowered the water pressure of her shower to reduce the rate at which the water comes out of the shower head by a quarter. By what fraction did Julia reduce the total amount of water she uses for a shower? Let's pose this question almost like a speed and distance problem and think about it that way. Initially, she spent time t in her shower. Because she reduced the time she spent in the shower by one quarter, now she spends time three quarters t. Analogously, she previously spent a flow rate r in the shower and she reduced that by a quarter. Now the flow rate she uses is three quarters r. Therefore, originally she spent r times t total water and she now spends three fourths t times three fourths r total water. Her total usage now is nine sixteenths rt which is a decrease of seven sixteenths from her original usage of rt. Therefore our answer is e.

Keywords

water conservation

shower reduction

flow rate

fraction decrease

water usage