Both those examples are correct. I think you're being confused by thinking you need to combine the "y -> ies" plural rule and the "s apostrophe" rule. Here are more examples. the boy's bicycle (1 boy, 1 bicycle.) the boys' bicycle (2+ boys, 1 bicycle.)

Anytime you use a word ending in "y" in the possessive tense (as you did above), you will add an apostrophe. EX: My country's mountains (the mountains belong to your country). If you were hoping to make a word ending in "y" plural (more than one) you would add an "s" without an apostrophe or you would change the "y" to "ies." EX1: I have a favorite toy, but I like to play with all my toys (you like one toy, but still play with more than one toy). EX2: I want to see mountains in many countries (there are mountains in more than one country that you want to see). With the plural rule, it is determined by the letter before the y: monkey: vowel + y = monkeys sky: consonant + y = skies