Question 3 - Figure it out - Page 67, 68 - Chapter 3 Class 8 - Proportional Reasoning-2 (Ganita Prakash II)

Transcript

Question 3 A tank on a building has enough water to supply 20 families living there for 6 days. If 10 more families move in there, how long will the water last? What assumptions do you need to make to work out this problem?Given that, 20 families use water supply in 6 days We need to find how long will water last if 10 more families move in there So, Total families are now = 20 + 10 = 30 Let the Time taken be y hours Now, we draw a table Now, as quantity of water is same As Number of families increase Number of days water lasts would decrease So, they are in Inverse Proportion So, we write numbers as 𝒙_𝟏 𝒚_𝟏 = 𝒙_𝟐 𝒚_𝟐 20 × 6 = 30 × 𝑦 (20 × 6)/30=𝑦 (2 × 6)/3=𝑦 4 = 𝑦 𝒚 = 4 So, water will last for 4 days The other part of our question is What assumptions do you need to make to work out this problem? To work this out, we must assume that Every single family consumes the exact same amount of water per day.