Question

Fred completed 10 math problems this is 40% of the math problems he must do how many are left??

Answer 1

10/100=10.01x50=4

fred has 4 problems left to do

Answer 2

$x-\ all\ problems\\\\ 40\%x=10\\\\ 0,4x=10\ \ \ \ | divide\ by\ 0,4\\\\ x=25\\\\ There\ were\ 25\ problems\ to\ solve.$