Container C and Container D were filled completely with bread flour. The total mass of ¹₃ of the bread flour in Container D and ¹₇ of the bread flour in Container C was 580 g. If ²₇ of the bread flour in Container C was poured out, the total mass of the bread flour in both containers became 2.1 kg. How much bread flour was in

1. Container C in grams?
2. Container D in grams?

(a)
Let the mass of the bread flour in Container D be D.
Let the mass of the bread flour in Container C be C.

¹₃ D + ¹₇ C = 580 --- (1)

Fraction of the bread flour left in Container C after ²₇ of it was poured out
= 1 - ²₇
= ⁵₇

1 kg = 1000 g
2.1 kg = 2100 g

1 D + ⁵₇ C = 2100
1 D = 2100 - ⁵₇ C --- (2)

Make D the same.

(1)_x3
³₃ D + ³₇ C = 1740
1 D + ³₇ C = 1740
1 D = 1740 - ³₇ C --- (3)

(3) = (2) 
1740 - ³₇ C = 2100 - ⁵₇ X
⁵₇ C - ³₇ C = 2100 - 1740
²₇ C = 360
¹₇ C = 360 ÷ 2 = 180

⁷₇ C = 7 x 180 = 1260

1 C = 1260

Mass of Container C = 1260 g

(b)
From (1)
¹₃ D + 180 = 580
¹₃ D = 580 - 180 = 400

³₃ D = 3 x 400 = 1200

1 D = 1200

Mass of Container D = 1200 g

Answer(s): (a) 1260 g; (b) 1200 g