Two containers A and B begin with equal volumes of liquid. 120 ml is then poured from A to B. Container B now contains 4 times as much liquid as A. Find the volume of liquid left in container A at the end.
Accepted Solution
A:
--------------------------------- Define A and B: --------------------------------- Let A be the volume of the liquid in container A at first. Let B be the volume of the liquid in container B at first.
--------------------------------- Construct equation : --------------------------------- 2 containers have the same liquid. ⇒ A = B
120 ml is then poured from A to B. Container B now contains 4 times as much liquid as A. ⇒ 4(A - 120) = (B + 120)
--------------------------------- Solve A and B : --------------------------------- A = B ------- (1) 4(A - 120) = (B + 120) ----- (2)
Sub (1) into (2) : 4(B - 120) = (B + 120) 4B - 480 = B + 120 3B = 480 + 120 3B = 600 B = 200
--------------------------------- Find A and B : --------------------------------- B = 200 ml A = B = 200 ml
Container A at the end = 200 - 120 = 80ml
--------------------------------------------------------------------------------------------------- Answer: Container A has 80m left. ---------------------------------------------------------------------------------------------------