5 % of items are defective in a box of 200 items.

∴ No. of defective items in the box = 200 × 5 / 100 =10 items.

3 items are selected from the box. Such that all three items are defective.

∴ Total combinations = ^{10}C_{2}

= \(\frac{10×9×8}{3×2×1}\)

= 720 / 6 = 120