A sample of 0.20 mol of 2-hydroxybut-3-ynoic acid, $\mathrm{HC}\equiv \mathrm{C}-\mathrm{CH}(\mathrm{OH})-\mathrm{COOH}$, is treated with excess $\mathrm{CH}{}_3\mathrm{MgBr}$ in dry ether. Assume every acidic hydrogen (the O-H of the acid, the alcohol O-H and the terminal alkyne C-H) reacts completely with $\mathrm{CH}{}_3\mathrm{MgBr}$ to release $\mathrm{CH}{}_4$, and no addition to carbon-oxygen bonds is counted. How many moles of $\mathrm{CH}{}_4$ are evolved? Give the answer to two decimal places.

Numerical answer type, tolerance 0.02.