@Kim1056,
1) percentage is easy 100% fractionally is 1.0 and o.o1 (1/100) is 1%
2) $4.20 is the same as 420 cents--now 420 is a composite number (product of prime numbers)--break it into primes
420=(10)*(42)=(2*5)*(6*7)=2*5*2*3*7
36 is also a composite number
36=4*9=2*2*3*3
so 420/36=(2*5*3*3*7)/(2*2*3*3)
now multiplication is communitative (2*3=3*2)
so you can cancel like terms in the numerator and denominator (2/2=3/3=4/4=1) and you have a 1 and a 3 in the numerator and denominator. This product is also called the Greatest Common Divisor (GCD)
420/36=(2*5*2*3*7)/(2*2*3*3)=(5*7)/(3)
now turn this back into the composite
and you'll bet the number of cents per potato, divide this by the bumber if cents in a dollar to get that number.
3) turn 2 3/5 into an improper fraction 2 3/5= 10/5+3/5=13/5
now 1=100% (just like in problem 1) so multiply 13/5 by 100 to get %
Rap