Six times a number, added to 7, is -11

The holiday party will cost $160 if 8 people attend. if there are 40 people who attend the party, how much will the holiday party cost

Prove that 16^4-2^13-4^5 is divisible by 11.

Two poles, ab and ed, are fixed to the ground with the of ropes ac and ec, as shown: what is the approximate distance, in feet, between the two poles? 6.93 feet 8.66 feet 12.32 feet 15.59 feet