Calculating the price elasticity of supply

Jake is a retired teacher who lives in New York City and does some consulting work for extra cash. At a wage of $50 per hour, he is willing to work 7 hours per week. At $65 per hour, he is willing to work 10 hours per week.

Using the midpoint method, the elasticity of Jake’s labor supply between the wages of $50 and $65 per hour is approximately ___ , which means that Jake’s supply of labor over this wage range is ___ .