While writing inequalities we should know about symbols
a>b means a is greater than b
a<b means a is less than b
so here we have to write
difference between t and 7= t-7
given t-7 is greater than 10 so t-7>10
and t-7 is less than 20 so t-7<20
combining above two we get
10<t-7<20, 17 < t < 27