Question

____centigram = 1.7 microgram

# of cg = 1.7ug x 1mg/1000ug x 1cg/10mg = 0.00017cg
but its wrong

___ milliseconds = 7 microseconds

# of ms = 7us x 1ms/1000us = 0.07us
but the answer key says its 0.007us

Answer 1

0.00017 cg looks ok to me. Perhaps you are supposed to enter 1.7 x 10^-4 cg. Also, sometimes the answer is counted wrong if you don't enter the unit.

For the second problem, 7 divided by 1000 = 0.007. Your set up is ok; you just didn't do the math correctly.

Answer 2

thank you DrBob