90 minutes doing homework, 2/3 hour reading, and 540 seconds making his lunch for the next day. How many more minutes did Roberto spend doing homework than he did reading and making his lunch?

41 minutes

Explanation:

According to this question;

- Roberto spent 90 minutes doing homework

- Roberto spent 2/3 hour reading. Since 1 hour = 60 minutes

2/3 hour = 2/3 × 60 = 40 minutes.

- Roberto spent 540 seconds making his lunch for the next day. Since, 60 seconds = 1 minute

540 seconds = 540/60

= 9 minutes.

The total amount of time Roberto spent reading and making his lunch is = 40 + 9 = 49 minutes.

Therefore, the amount of time Roberto spent doing his homework than reading and making his lunch is (90 - 49) = 41 minutes.

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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