Actress Vidya Balan on Thursday took to Instagram and announced the release date of her upcoming film "Shakuntala Devi" in a quirky way.As the film is based on the life of the late mathematics genius Shakuntala Devi, Vidya teased her followers with a math problem to decode the release date on their own."Hi, everyone. I have some exciting news to share. The release date for 39Shakuntala Devi39 has been decided and it will release in exactly 148 days from now," she said in the clip."Kya hua? Calculation nahi kar paa rahe? Kya laga, Shakuntala Devi hoon, aise hi bata dungi? Chalo, one more try. What happened? Unable to calculate? Did you think Shakuntala Devi would give you the answer just like that? Okay, one more try," she added.Then she gave another math problem."It is release on the date which is a number 8, when added with the month and year number, again adds up to 8," she said.Not only this, she also asked her fans to guess the release date with emojis, before revealing the answer.The film also stars Sanya Malhotra as Shakuntala Devi39s daughter Anupama and Amit Sadh in a pivotal role.