Question

a school library has a hundred and twenty DVDs in its collection given that 45% of the DVDs are about science and 35% are about history how many of the DVDs are about other subjects

Answer 1

20% of the DVDs are about other subjects

Answer 2

45 % + 35% is 80%
80% of 120 (.80 times 120) = 96
120-96= 24
24 of the books are other subjects