At a rate of 6 breaths per minute with an I:E ratio of 1:2, what is the approximate inspiratory time for each breath?

At a rate of 6 breaths per minute with an I:E ratio of 1:2, what is the approximate inspiratory time for each breath?

• A. 1.8 seconds
• B. 2.5 seconds
• C. 3.3 seconds
• D. 4.0 seconds

Answer: (C)

Think of the breathing cycle length and how the I:E ratio divides that cycle. At 6 breaths per minute, each full breath takes 60 seconds / 6 = 10 seconds. The ratio 1:2 means the cycle is split into three equal parts: one part for inspiration and two parts for expiration. So inspiratory time is one third of the 10-second cycle: 10 ÷ 3 ≈ 3.33 seconds. The closest value is about 3.3 seconds. The other numbers don’t match the one-third share of a 10-second cycle dictated by the 1:2 ratio.

Think of the breathing cycle length and how the I:E ratio divides that cycle. At 6 breaths per minute, each full breath takes 60 seconds / 6 = 10 seconds. The ratio 1:2 means the cycle is split into three equal parts: one part for inspiration and two parts for expiration. So inspiratory time is one third of the 10-second cycle: 10 ÷ 3 ≈ 3.33 seconds. The closest value is about 3.3 seconds. The other numbers don’t match the one-third share of a 10-second cycle dictated by the 1:2 ratio.