Wifi Range Extender??

The extender is about 75 feet away from router....house is an old cylinder block has...in fact my daughter lives in it and they have problems getting wifi to the back bedroom...
the computer in the garage could pick up the house router but it was a week signal....so 30 bucks for the extender I get a very strong signal and excellent download speeds,,,I dont have any problem using the computer on line and tv at the same time thru the switch box....

The second router is a netgear that is a few years old....and once I ran cat 5 cable to it and fire it up...I login into the old router...and it immediate changed it IP address not conflict with the house router...and bingo....been working since...