Copier A prints at a rate of 117 letters in every 3 minutes and Copier B prints at a rate of 144 letters in every 6 minutes. At 3 p.m., both copiers started printing. After a while, Copier A stopped printing for some time as the ink cartridges were being changed before it continued to print again. Copier B continued printing during this time. At 7 p.m., the total number of letters printed during the past four hours was 8627. Express the number of letters printed by Copier A 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 A prints per min = 117 ÷ 3 = 39
Number of letters Copier B prints per min = 144 ÷ 6 = 24

From 3 p.m. to 7 p.m. = 4 h
1 h = 60 min
4 h = 240 min

Number of letters printed by Copier B in 3 h
= 240 x 24
= 5760

Number of letters printed by Copier A in 3 h
= 8627 - 5760
= 2867

Percentage of the number of letters that Copier A printed over the total number of letters printed
= ²⁸⁶⁷₈₆₂₇ x 100%
≈ 33.23%

Answer(s): 33.23%