Copier N prints at a rate of 84 letters in every 2 minutes and Copier P prints at a rate of 156 letters in every 4 minutes. At 2 p.m., both copiers started printing. After a while, Copier N stopped printing for some time as the ink cartridges were being changed before it continued to print again. Copier P continued printing during this time. At 4 p.m., the total number of letters printed during the past two hours was 8463. Express the number of letters printed by Copier N as a percentage of the total number of letters printed by both copiers. Round off your answer to 2 decimal places.
Number of letters Copier N prints per min = 84 ÷ 2 = 42
Number of letters Copier P prints per min = 156 ÷ 4 = 39

From 2 p.m. to 4 p.m. = 2 h
1 h = 60 min
2 h = 120 min

Number of letters printed by Copier P in 2 h
= 120 x 39
= 4680

Number of letters printed by Copier N in 2 h
= 8463 - 4680
= 3783

Percentage of the number of letters that Copier N printed over the total number of letters printed
= ³⁷⁸³₈₄₆₃ x 100%
≈ 44.70%

Answer(s): 44.70%