my average score on 8 math test is 90. If my average on the first 5 test was 87, what was my avergae score on the last 3 test?
360°
To see this....draw a diagonal connecting any pair of opposite vertices
This will split the trapezoid into two triangles....
The interior angles of each triangle will sum to 180°
So ...2 * 180° = 360°
Mmmmmm.....the question seems to have changed....LOL!!!
We need 8 *90 = 720 points on the 8 tests
So
720 - 5(87) = 285 remaining
So....we need to average
285 /3 = 95 on the last three