Final answer:
The typewriter types 36 letters in 8 cm. To find the number of letters that can be typed in 35 lines, each 12 cm long, we multiply the rate of letters per cm by the length of each line and the total number of lines.
Explanation: The typewriter types 36 letters in 8 cm. We need to determine how many letters can be typed in 35 lines, each 12 cm long.
Let's start by finding the number of letters typed in 1 cm. We divide 36 letters by 8 cm, which gives us 4.5 letters per cm. Now we can multiply this rate by the length of each line (12 cm) and the total number of lines (35) to find the total number of letters typed.
Total letters = Rate per cm × Length of each line × Total number of lines
Total letters = 4.5 letters/cm × 12 cm × 35 lines = 1890 letters
The typewriter can type 1890 letters in 35 lines, each 12 cm long. Therefore, the correct option is D) 420 letters.