Question

Add the following
$3$ hours $18$ minutes $22$ seconds and $2$ hours $27$ minutes $31$ seconds.______

Answer 1

$3$ hours $18$ minutes $22$ seconds $=3\times 60\times 60+18\times 60+22$ sec $=11902$ sec

$2$ hours $27$ minutes $31$ sec $=2\times 60\times 60+27\times 60+31$ sec $=8851$ sec

Adding $3$ hours $18$ minutes $22$ seconds and $2$ hours $27$ minutes $31$ seconds gives $11902+8851=20753$ sec $=5\times 60\times 60+45\times 60+54=5$ hours $45$ min $54$ sec