A sample of a radioactive isotope had an initial mass of 490 mg in the year 1995 and decays exponentially over time. A
measurement in the year 1998 found that the sample's mass
had decayed to 240 mg. What would be the expected mass of
the sample in the year 2005, to the nearest whole number?

answer:

c 60% on edg

  the correct choice is marked

step-by-step explanation:

the first two graphs show multiple turning points. the last graphs matches the description in every detail.

the correct option is 2.

step-by-step explanation:

according to the given information triangle abc is a right angle triangle with right angle at a. segment ab is 5 and segment ac is 7. point d is on segment bc and angles adb and adc are right angles.

it is given that triangles abd, cad, and cba are similar.

two triangles are similar if their corresponding sides are proportional.

in triangle cba, using pythagoras theorem

                      )

triangle abd and cba are similar,

                            (2)

triangle cad and cba are similar,

                      )

using (1), (2) and (3), we get

hence proved.

therefore option 2 is correct.