The energy of a certain particle is 3.86 joules. If this particle loses 0.105 joule of energy every 30..

The energy of a certain particle is 3.86 joules. If this particle loses 0.105 joule of energy every 30 seconds, what will its energy be after 8 minutes?
The answer is 2.18 joules but how do I solve this problem?

Note that, since 8 minutes = 8*60 = 480 seconds, the particle will lose 0.105 J of energy 480/3 = 16 times. Therefore, the final energy of the particle after 8 minutes is:
E = 3.86 - 16(0.105) = 2.18 J, as required.

I hope this helps!