If 90 percent of the office has less than 10 years service, then 10% has at least 10 years. We know that there are 16 people with at least 10 years and that represents 10 percent of the workforce. Now we can solve for the number of employees, x, as follows:

.1x=16

x=160

If 40 percent have at least 5 years, then that represents 64 workers (160 * 0.4). The question asks for "at least 5 years, but less than 10" so it's 64 - 16 = 48

Hope this helps.

i did the same as ryan did..
total 160
16 are >10 and
60% less than 5

hence 160-16-96 = 48.

hope its clear..

I am sure its a typo by Ryan its 64-16 = 48 and not 64- 18.

Thanks for the catch. I usually do the problems on paper first and then transcribe. Must be my Homer-Simpson-like fat fingers...