Hall Pass

Rick (Owen Wilson) and Fred (Jason Sudeikis) are best friends as are their wives, Maggie (Jenna Fischer) and Grace (Christina Applegate). They are both unhappy with their sex lives and missing the old days when they were single. Realizing this, their wives decide to give them a "hall pass": A week off from marriage, in which they can have sex with other women. They are skeptical at first, but ultimately accept the offers and try to pick up women with their friends Gary (Stephen Merchant), Flats (J.B. Smoove), and Hoghead (Larry Joe Campbell). Maggie and Grace spend Rick's and Fred's Hall Pass Week at Maggie's parents' house in Cape Cod, where Grace flirts with athlete Gerry (Tyler Hoechlin), saying that if their husbands have hall passes, so should they.With their wives and children away, Fred and Rick check into a motel and prepare for their Hall Pass Week. On Day One, they decide to eat before going to a local bar and get too tired to spend the night there, preferring to stay at the hotel.On Day Two, they eat pot brownies and decide to play golf, but get too high and wreak havoc on the golf course.On Day Three, they go to Hooters with their friends, but fail to impress the women there. They decide to get drunk in order to loosen up, but go too far and wind up getting into a fight with other customers. They spend Day Four at the hotel, suffering from a hangover.On Day Five, Rick goes to a local coffee shop, where he flirts with an attractive waitress called Leigh (Nicky Whelan), much to the annoyance of her co-worker Brent, who insults Rick. When Rick answers him back, Leigh is impressed and tells Rick that they might see each other at the local gym they both attend. They later meet there, and Leigh invites Rick for a beer after they work out. Rick decides to go to a sauna instead, but falls asleep and stays there too long, getting burned and being forced to accept the help of two naked men to leave, much to his dismay. Meanwhile, Grace and Gerry get closer, while Maggie finds herself attracted to Gerry's coach.On Day Six, Rick and Fred go to a bar called Enter the Dragon with their friend Coakley (Richard Jenkins), where Rick meets his children's babysitter Paige (Alexandra Daddario), who has just turned 21 and is with her aunt. Paige is attracted to Rick, but he shoots her down to dance with Leigh. Brent, the DJ, is angry at this. Afterwards, Rick goes to party at Coakley's while Fred takes a girl to his motel room. However, she feels sick and, after a minor incident in the bathroom, is sent back home by Fred before they had sex. Later this evening Paige's aunt shows up at the room and mistakes Fred for Rick, eventually seducing him. Fred fakes oral sex on Paige's aunt, until they are interrupted by Rick.Meanwhile, Maggie is seduced by Gerry's coach, but rebuffs him. Grace, on the other hand, has sex with Gerry, but tells him it'll be just that one time. On her way back home, she feels guilty about cheating on Fred and has a car accident.At Coakley's house, Rick meets Leigh, who offers him a one-time fling. He initially wants to do it, but ultimately rebuffs her, unable to cheat on Maggie. As he is leaving after hearing of Grace's accident, he is approached by Brent, who is angry at Rick because he thinks Rick had sex with Leigh, who calms him, and Rick makes his way to the hotel, where he finds Paige, who thinks Rick was having sex with her aunt. They enter the room and find Fred having sex with Paige's aunt. After finding out the truth, Paige kicks Fred in the face.Upon hearing about Grace's accident, Fred tries to go to the hospital, but finds Brent vandalizing Rick's car. Upon seeing Paige's aunt -- his mother -- at the hotel, Brent thinks Rick has had sex with her and tries to kill Rick, but runs out of bullets and is tackled by Paige and his mother. Rick and Fred enter Fred's car and make their way to the hospital, with Brent and the police chasing them. At the hospital, Brent is arrested for attacking them and Fred finds out Grace only broke her nose.Rick goes back home and finds Maggie. He tells her he did not use the hall pass and that he lost his virginity to her. She is the only woman he has ever been with. Moved by his declaration, Maggie tells him she did not use her hall pass either and they reconcile and have sex for the first time in months.Fred and Grace also reconcile and decide to hide their cheating from one another. However, Fred ultimately confesses that he used his hall pass with Paige's aunt when Grace asks him to take her to see Kathy Griffin.

Question: How old was Rick's children's babysitter?
Answer: Twenty one