Answer:
Amount of B used = 276.6 millimeters
Step-by-step explanation:
A = A millimeters
B = A + 400 millimeters
Hence
Taking an overall balance
(0.16 x A) + (0.2)(A+400) = 476
0.16A + 0.2A + 80 = 476
A = 1100 millimeters
B = 1100 + 400 = 1500 millimeters
Hence using direct proportion
2600 --------------------476
1500 ---------------------X
X = 276.61538
Amount of B used = 276.6 millimeters