9. she spends 1 hour total and 1/2 hour on spanish. So she has another 1/2 on another subject ( as she spends equal time on each subject)
So number of subjects = 1 / 1/2 = 1 * 2 = 2
Park p :
18/82 = 0.219 = 21.9% green birds
park q :
39/88 = 0.443 = 44.3% green birds
park r :
38/64 = 0.593 = 59.3% green birds
park service :
22/50 = 0.44 = 44%
park with greatest percentage of green birds is park r <==
The best estimate is probably 4
So 5^2 -4^2 is 25-16 which is 9
6^2/9 is 36/9 which is 4 +9 is 13
13(13) is 169