Answer:
39.9km a day
Step-by-step explanation:
Add up the four kilometers cycled and you should get 159.6km cycled in total. Divide that number by 4 to get 39.9km as a result. So she's wrong.
The answer is 8. 40 / 31 = 1.29032258. Multiply that by 6 and you have 7.74193548. Round up because you can't buy 7.7 cans of dog food.
15x = 500-50
15x = 450
x = 450/15
x =30
Thus, x is equal to 30.