Question

First drilled to a depth of 1 47/64 how much deeper must it be drilled to reach the depth indicated?

Answer 1

Answer:

  1 13/64

Explanation:

The depth of the hole is the height of the block less the remaining material below the hole:

  depth = 1 3/8 +1 15/16 - 3/8 = (1 3/8 -3/8) +1 15/16 = 2 15/16

We want to find the difference between this depth and the depth of the hole already drilled:

  2 15/16 -1 47/64 = 2 60/64 -1 47/64

  = (2 -1) +(60 -47)/64 = 1 13/64

The hole must be drilled 1 13/64 deeper to match the drawing.