Yahoo! 3 years ago 12.5% of an isotope remains after 8 years from the initial stage. After 8 more years the quantity persent will be?

1. sauravshakya

first find half- life.can u?

2. sauravshakya

@Yahoo!

3. Yahoo!

Let me try

4. Tomas.A

it... will... be... posted in physics group

5. sauravshakya

@Yahoo! u there

6. Yahoo!

nop....it is maths question ... in sequence and series

7. Tomas.A

lol ok

8. Yahoo!

No ... Idea

9. sauravshakya

First |dw:1344690805456:dw|

10. sauravshakya

here x is the initial amount of the isotope

11. sauravshakya

can u find common ratio.......

12. sauravshakya

or u can do it as |dw:1344690939900:dw|

13. sauravshakya

|dw:1344690979564:dw|

14. sauravshakya

|dw:1344691068840:dw|now find

15. sauravshakya

can u? @Yahoo!

16. Fellowroot

17. ganeshie8

\(.125 = e^{8r}\)

18. ganeshie8

@Fellowroot has it !

19. sauravshakya

|dw:1344691170393:dw|

20. jcyogi

people this girl needs help ---------> tafara27

21. sauravshakya

so the answer is 1.56 percent

22. sauravshakya

can also be done using simple maths......

23. sauravshakya

do u want me to do that? @Yahoo!

24. Yahoo!

@sauravshakya the answer should be 25/16 %

25. sauravshakya

|dw:1344692147133:dw|

26. Yahoo!

hw did u get that

27. Yahoo!

i got it thxxx

28. sauravshakya

ok.....

29. sauravshakya

welcomx