average of money that group of 4 friends pay for rent each month is $ 800 . after one persons rent is increased by 20 % the new mean is $ 880 . what was original rent of friend whose rent is increased ?
0.2 x = 4 ( 880 - 800 ) 0.2 x = 320 x = 1600 answer c
divide(multiply(subtract(880, 800), 4), divide(20, const_100))