Answer :
create an equation where x equals extra messages
15 + .05X = 24.60
.05x = 9.60
x=192
So she sent 192 EXTRA messages. Add this to the original 600 and you get 792 messages
15 + .05X = 24.60
.05x = 9.60
x=192
So she sent 192 EXTRA messages. Add this to the original 600 and you get 792 messages