In a single pass drilling operation, a through hole of $15 \mathrm{~mm}$ diameter is to be drilled in a steel plate of $50 \mathrm{~mm}$ thickness. Drill spindle speed is $500 \mathrm{rpm},$ feed is $0.2 \mathrm{~mm} / \mathrm{rev}$ and drill point angle is $118^{\circ} .$ Assuming $2 \mathrm{~mm}$ clearance at approach and exit, the total drill time (in seconds) is

(A) 35.1

(B) 32.4

(C) 31.2

(D) 30.1

In a single pass drilling operation, a through hole of $15 \mathrm{~mm}$ diameter is to be drilled in a steel plate of $50 \mathrm{~mm}$ thickness. Drill spindle speed is $500 \mathrm{rpm},$ feed is $0.2 \mathrm{~mm} / \mathrm{rev}$ and drill point angle is $118^{\circ} .$ Assuming $2 \mathrm{~mm}$ clearance at approach and exit, the total drill time (in seconds) is

(A) 35.1

(B) 32.4

(C) 31.2

(D) 30.1

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