Element X is a radioactive isotope such that every 66 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 240
grams, how much of the element would remain after 20 years, to the nearest
whole number?

194.5315427 grams

Step-by-step explanation:

The half-life of element x would be 66 years. So, after 20 years you would have:

.5^(20/66) x 240=0.810548 x 240

        =194.5315427 grams of the element left

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.

the photograph is photographer and- in the process- ourselves.

step-by-step explanation: