One fourth of all telephones at the office have built in speaker phones. one -half the phones with the built-in speaker phones have conference-call capability, how many of the phones in the office have both a speaker phone and a conference-call capability?

of the phones in office has both a speaker phone and a conference-call capability

Step-by-step explanation:

Since total number of phones in the office is not given, the answer will be "in that terms".

let it be x

So built in speaker phones is (1/4)x

Hence conference call phones would be (1/2)(1/4x) = (1/8)x

Hence "1/8th of the phones in office has both a speaker phone and a conference-call capability"

justin bieber ml.

x = -5

step-by-step explanation: