A memory system consists of a cache and a main memory.

It takes $15$ns to access the cache, and $100$ns to access the main memory. This means, per Subject $1$ notes, that if the datum is not available in the caches we wasted $15$ns$,$ and thus in additional $100$ns we access the main memory and obtain the datum.

If the effective memory access time is $40\%$ greater than the cache access time, what is the miss ratio M $?$

Express M as an integer between $0($inclusive$)$ and $100($inclusive$).$ Thus if you think the miss ratio is $10\%$ you write $10,$ and neither $10\%$ nor $0\mathrm{.}1.$