Copier U prints at a rate of 114 letters in every 2 minutes and Copier V prints at a rate of 128 letters in every 4 minutes. At 2 p.m., both copiers started printing. After a while, Copier U stopped printing for some time as the ink cartridges were being changed before it continued to print again. Copier V continued printing during this time. At 4 p.m., the total number of letters printed during the past two hours was 8718. Express the number of letters printed by Copier U 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 U prints per min = 114 ÷ 2 = 57
Number of letters Copier V prints per min = 128 ÷ 4 = 32

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

Number of letters printed by Copier V in 2 h
= 120 x 32
= 3840

Number of letters printed by Copier U in 2 h
= 8718 - 3840
= 4878

Percentage of the number of letters that Copier U printed over the total number of letters printed
= ⁴⁸⁷⁸₈₇₁₈ x 100%
≈ 55.95%

Answer(s): 55.95%