Answer:
102.3
Step-by-step explanation:
a_38 = -5
difference d= -2.9
We use general formula

WE make the formula for a_38 th term
Plug in 38 for n

Now plug in -2.9 for d and -5 for a_38


Now add 107.3 on both sides
102.3 = a_1
option A is correct
A+7=0
A+7-7=0-7
A=-7
B+3=7
B+3-3=7-3
B=4
Answer:
Step-by-step explanation:
Half life is the time taken by a radioactive substance to reduce of half of its original size
If the half life of radium is 1600, this means that the original radioactive substance N0 have reduced to N0/2 after 1600 years
if we are given N0 = 1000grams
The amount of the substance that will remain after 1600 years will be N0/2 i.e 1000/2 = 500g
<em>Hence 500 grams of radium will be left after 600years</em>