Take the 89 times 5 tests. You get 445 total score you need for an average of 89. Add 82, 89, 92, 87=350 445-350=95 They must get a 95 on next test to get the average of 89
Just put them in order from least to greatest and find out in between which number to put them . For example put 24 between 20 and 25.
Hope that helps .
Sadie= 82
Buddy= 54
Divide by 2, 136/2=68, then rest 14 to one half, 68-14=54, next add the other half 14, 68+14=82.
There you have it, i hope it helps you