SOLUTION
We have been given the equation of the decay as
So we are looking for the time
Plugging the values into the equation, we have
Taking Ln of both sides, we have
Hence the answer is 4308 to the nearest year
<span>1. multiply to -18
add to -17 = Multiplying -18 and 1 will give -18 as the result and then on
adding -18 and + 1 the result comes to -17
</span><span>2. multiply to 36 add
to -13 = Multiplying -9 and -4 will give -36 as the result and then on
adding -9 and -4 the result comes to -13
</span><span>3. multiply to -24 add to -5<span>= </span></span><span>Multiplying -8 and +3 will give -24 as the result and then on
adding -8 and +3 the result comes to -5
4. multiply to -18 add to 7= </span><span>Multiplying +9 and -2 will give -18 as the result and then on
adding +9 and -2 the result comes to 7
5. multiply to -36 add to 9= </span><span><span>Multiplying +12 and -3 will give -36 as the result and then on
adding +12 and -3 the result comes to 9
</span> 6. multiply to 24 add to 10= </span><span><span>Multiplying +6 and +4 will give 24 as the result and then on
adding +6 and +4 the result comes to 10
</span> 7. multiply to 18 add to -9= </span><span><span><span>Multiplying -6 and -3 will give -18 as the result and then on
adding -6 and -3 the result comes to -9
</span> 8. multiply to -36 add to -16</span>= </span><span>Multiplying -18 and +2 will give -36 as the result and then on
adding -18 and +2 the result comes to -16</span>
See the attached picture.
Since you know what 4×5 is you just have to use the same answer
