Question

Container a and b hold 11,875 liters of water altogether. Container b holds 2,391 liters more than container a holds. How much water does container a hold?

Answer 1

Container A holds x liters of water.
Container B holds 2391 liters of water more than container A, so container B holds x+2391 liters of water.
Container A and B hold 11875 liters of water altogether.

$x+x+2391=11875 \\ 2x+2391=11875 \\ 2x=11875-2391 \\ 2x=9484 \\ x=\frac{9484}{2} \\ x=4742$

Container A holds 4742 liters of water.