A box contains 280 coins of one rupee, 50 paise and 25 paise. The value of each kind of the coins are in the ratio of 8 : 4 : 3. Then the number of 50 paise coins is

\[\begin{array}{*{20}{c}} {}&{{\text{Rs}}{\text{. 1}}}&:&{50\,{\text{Paise}}}&:&{25{\text{ Paise}}} \\ {{\text{Value of coins}}}&{8x}&:&{4x}&:&{3x} \\ {{\text{Number of coins}}}&{8x \times 1}&:&{4x \times 2}&:&{3x \times 4} \\ {}&{8x}&:&{8x}&:&{12x} \end{array}\]
∴ Total coins ⇒ 8x + 8x + 12x = 28x
28x = 280   (Given)
x = \[\frac{{280}}{{28}}\] = 10
∴ Number of 50 paise coins are = 8x = 8 × 10 = 80