tag:blogger.com,1999:blog-5541500.post4041063056501733364..comments2021-09-17T10:32:26.164+09:00Comments on BigHominid's Hairy Chasms: this week's Math Beast Challenge problemKevin Kimhttp://www.blogger.com/profile/01328790917314282058noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-5541500.post-28823049109710427162011-12-13T05:22:44.058+09:002011-12-13T05:22:44.058+09:00I hit "publish" on your comment but refu...I hit "publish" on your comment but refused to look at the answer so that I could try solving this for myself. It's scary that we ended up using exactly the same method. I agree that the answer is (A).Kevin Kimhttps://www.blogger.com/profile/01328790917314282058noreply@blogger.comtag:blogger.com,1999:blog-5541500.post-22598965176322188292011-12-13T04:20:26.298+09:002011-12-13T04:20:26.298+09:00The answer is (A) 40.
Let x = days of cardio alon...The answer is (A) 40.<br /><br />Let x = days of cardio alone @ 500 cal/day and let y = days of cardio and weight training @ 1100 cal/day.<br /><br />We can set up simultaneous equations as follows:<br /><br />(1) x + y = 240<br /><br />(2) 500x + 1100y = 240(850) = 204000<br /><br />Simplifying (2), we get 5x = 2040 - 11y<br />From (1) we know that x = 240 - y, so 5x = 1200 - 5y<br /><br />1200 - 5y = 2040 - 11y<br /><br />6y = 2040 - 1200 = 840<br /><br />y = 840/6 = 140<br /><br />From (1), we know that x = 100<br /><br />The answer to the question is y - x, which equals 40.Elissonhttps://www.blogger.com/profile/06299361897381169534noreply@blogger.com