$7-1.($Calculating rates of return$)($Related to Checkpoint $7\mathrm{.}1$ on page $232)$ The shares ofand get instant feedback.Tesco PLC were worth $2\mathrm{.}51$ on April $10,2015.$ They were trading at $1\mathrm{.}90$ one year later.Assuming they did not pay any dividend in that year, what was the return offered by Tesco's shares during this period?