we are given
62% of the students take math
so,
49% take science
38% take both science and math
n(M∩S)=38
now, we can use union formula
n(M∪S)=n(M)+n(S) -n(M∩S)
now, we can plug values
and we get
n(M∪S)=62+49 -38
n(M∪S)=73
so,
the percentage takes at least one science or math course is 73%..........Answer