DAY 70
3/7 of what number is 5/21

Answer:

5/9

DAY 71
In a field of cows, the difference between the number of ears and the number of legs is 40. How many cows are in the field?

Answer:

20..........the difference between ears and legs is 2 per cow. 40/2 = 20........or, since there are 1/2 as many ears as legs, the difference of 40 must be the number of ears.