a level biology math question!!!,

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Can someone please explain this to me.
The answer in the mark scheme was 110 days but I’m not sure how they got that answer

(edited 11 months ago)

Reply 1

TypicalNerd

Original post by hoyam

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Can someone please explain this to me.
The answer in the mark scheme was 110 days but I’m not sure how they got that answer

Well, start by taking the following readings:

(i) The protective antibody concentration
(ii) The concentration of antibodies after the third injection.

It tells you that the rate at which the antibody concentration decreases is 0.027 units per day, so if we let the time taken for the concentration to fall to the protective concentration be ‘d’ days, then the fall in the concentration will be 0.027d.

Can you use this, and the readings from the graph to write an equation that you can solve for d?