football cards and basketball cars respectively, follow the ratio 42:28
In order to simplify a ratio, or a fraction, or anything, you need to find the HCF (highest common factor) that goes into both 42 and 28. It must be a whole number, and must also equal a whole number. Once, you find this, divide it with the ration, respectfully.
Thus,
42 ÷ 7 = 4
28 ÷ 7 = 6
∴ simplified fraction is 4:6
Hope this helps :)