সাধারণ গণিত→অধ্যায় ০৪ঃ গতিবিদ্যা→সময়, দূরত্ব, বেগ

On Tuesday Ray rode his bike 10 miles. On Wednesday he increased Tuesday's distance by 5 miles. On Thursday he decreased Wednesday's distance by 7 miles. On Friday he increased Thursday's distance by 12 miles. How many total miles did Ray ride over the 4- day period ?