Rey and his sister have $23.
each taco is 30 cents, $0.30.
so say, let's check a tacos' price table
1 taco.................. 0.30(1)
2 tacos................0.30(2)
3 tacos................0.30(3)
4 tacos................0.30(4)
C tacos................0.30(C)
if they bought "C" tacos, they spent 0.30C for all tacos, however their wallet isn't infinite, they only have $23, so, whatever they spent on tacos, has to be $23 at most, it could be less, 22, 15 or so, but it can't be more than $23, unless they magically are pulling bills out of their sleeves, but they're not. So whatever 0.30C is, has to be less than or equals to 23.
0.3C ⩽ 23.
