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How many natural numbers exist in the range 142858 to 999999 inclusive, such that :
a. None of them is a multiple of 5.
b. The digit 3 is not contained in the number
D1 Please provide your estimate solution (p & p)
D3. Evaluate the exact result.
Four circles are tangent to each other and to a triangle that surrounds them, as shown in the figure. Each of the three circles in the corners have a radius of 1 cm. What is the radius of the circle in the middle?
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