$16\mathrm{.}3.$ Assume that $10$ errors have been introduced in the requirements model and that each error will be amplified by a factor of $2$:$1$ into design and an additional $20$ design errors are introduced and then amplified $1\mathrm{.}5$:$1$ into code where an additional $30$ errors are introduced. Assume further that all unit testing will find $30$ percent of all errors, integration will find $30$ percent of the remaining errors, and validation tests will find $50$ percent of the remaining errors. No reviews are conducted. How many errors will be released to the end users? $16\mathrm{.}4.$ Reconsider the situation described in Problem $16\mathrm{.}3,$ but now assume that requirements, design, and code reviews are conducted and are $60$ percent effective in uncovering all errors at that step. How many errors will be released to the field?