When is World Osteoporosis Day being observed?

Select the correct combination of mathematical signs that can sequentially replace ‘*’ sign and balance the equation given below.

If ‘P’ means (÷), ‘Q’ means (×), ‘R’ means (+), and ‘S’ means (-), then what is the value of the expression:

(19 % 3) * 11 = 2 and 9 * 3 % 2 = 5. Then, 8 % 4 * 2 = ?

Which two signs should be interchanged to make the following equation correct?

7 × 6 ÷ 3 – 6 = 40 + 20

If 30 – 22 means 660, 220 + 11 means 20, 14 ÷ 7 means 21, 15 x 12 means 3, then ' 333 – 8 x 255 ÷ 490 + 7 x 32 ' = ?

If '+' means '–', '–' means '×', '÷' means '+' and '×' means '÷', then ' 30 – 12 + 20 × 10 ÷ 10 ' = (?)

If 34 – 28 means 952, 544 + 8 means 68, 20 ÷ 5 means 25, 20 x 10 means 10, then 375 – 11 x 270 ÷ 550 + 11 x 35 = ?

If + means ÷, × means –, – means × & ÷ means +, then 32 + 16 – 13 x 18 ÷ 2 = ?