Simone has 20 bills. one fifth of the bills are hundreds, 1/4 of them are fifties, 1/10 of them are $20s. the rest of the bills are tens.
simone has$780 altogether. how many of each kind of bill does she have

Answer this question! 30 points and brainliest! only if you know the answer.

Two airplanes start at the same place and travel in opposite directions,one at 395 miles per hour and the other at 422 miles per hour. how many hours will it take for the planes to be 2451 miles apart?

Astudent draws two parabolas on graph paper. both parabolas cross the x-axis at (–4, 0) and (6, 0). the y-intercept of the first parabola is (0, –12). the y-intercept of the second parabola is (0, –24). what is the positive difference between the a values for the two functions that describe the parabolas? write your answer as a decimal rounded to the nearest tenth