Question 474696
You would use logarithms:
{{{6.02X10^(-4) = 0.153^(-N)}}} Take the log (common) of both sides.
{{{Log[10](6.02X10^(-4)) = Log[10](0.153^(-N))}}} Apply the "power rule" to the right side.
{{{Log[10](6.02X10^(-4)) = -N*Log[10](0.153)}}} Divide both sides by {{{Log[10](0.153)}}}
{{{-N = (Log(6.02X10^(-4)))/(Log(0.153))}}} Evaluate using your calculator.
{{{-N = 3.9429}}} so...
{{{N = -3.943}}} Rounded.