The ratio of the hyper to the insouciant was M to R. If K were being considered, how many were insouciant?
The ratio is: M/R
If this ratio is the original ratio, not reduced, this would be correct: M + R = K; so R = K - M.
However, if this is a reduced ratio, then we need to find a value x such that M/R = Mx/Rx and Mx + Rx = K.
Solving this, we get: Rx = K - Mx and R = (K - Mx) / x.