As Joe was trying to reminisce the past, he realized how his life has changed. He remembered that when he first started in his job he was only getting paid 12,800 and with such salary he can still vividly remember how had to buy 10 cans of sardines every payday. He also recalled that later on his salary was initially increased to 15,800 allowing him to buy not just 10 cans of sardines but 12. As he continues to contemplate Joe smiled as he realized that it's interesting that now that he is being paid P50,000 he doesn't buy sardines anymore. a) What is Joe's income elasticity after his salary was first increased? what type of good did Joe see sardines back then? b) What about at present? what is Joe's income elasticity? Is how he perceived sardines as a type of good changed? why?