An irrational number/value is one you cannot express in terms of a ration, or a fraction, it cannot be written as fraction
now 291.87... is simple, two decimals, so you use two zeros at the botom and end up with

and boom, there you are, a fraction, nice and dandy
now, let's see the first one -√(127) well, low and behold, 127 is a prime number, and and thus is has no two factors that'd serve as root, so, there's no rational root that'd give that, that makes it irrational
1 is false, 2 is true, 3 is false, 4 is false
I Think he weighs 27 pounds now correct me if i'm wrong
all of them is not a quadratic equations
well, let's see the 10-pack is $15.37 BUT each of those 10 bars are 2.1 oz, so for the whole package you're getting really 10 * 2.1 = 21.0 oz.
the 12-pack costs $15.35 BUT each of those 12 bars are 1.4 oz, so for the whole package you're getting 12 * 1.4 = 16.8 oz.
which is the better deal? which one gives you more ounces for the money? after all, you're going to eat the bars, so you want more ounces, not more bars.

so clearly you'd want to get the cheapest one with more ounces, so at $0.73 or 73 cents for each ounce, the 10-pack is the cheapest.