Solve This (? + ? + ?=30)

If 1111=R, 2222=T, 3333=E, 4444=N Then 5555=?

Guess the Hindi Muhawara from the following whatsapp Emoticons?

Sweet, Medicine, Film, Girl, City, Car, Place, Doggy all are name same, guess which word it is?

Guess me who am I, I am the first on earth, the second in heaven...

Which father and son, 17th and 18th century composers, between them lived in Rome, Naples, Florence and Madrid and composed over 120 operas, 600 chamber cantatas, and 500 harpsichord sonatas?

What invention in the 17th century revolutionized mathematics by providing the first systematic link between Euclidean geometry and algebra, describing geometric shapes as algebraic equations involving the coordinates of the points lying on it?