If you look up a calorie table, it says that a pastry of 50 grams contains 250 kcal. If you instead throw in the same amount of gingerbread, 50 grams, you get 230 kcal. (A large jar contains about 450 grams.) When you have ingested so much energy, you want to make something good out of it as well. According to calculations, a person in the range of 55-80 kg can cycle for 60 minutes and rest for 10 minutes on a pastry. On 50 grams of gingerbread you can cycle for 50 minutes and rest for 30 minutes. (You should then cycle in calm winds and 10 km / h or to lie down and just soften.) How much energy do you consume per 10 minutes when cycling or resting? (Tips from the coach: Do you remember the section on systems of equations?) How?? What do I write as x and y?