Question

Sam is eating a Big Hamburger. The first bite was 20% of the Hamburger, the second bite was 20% of what is left and so every next bite is 20% of what is left. a How much did the Hamburger weigh originally, if after the second bite there was 160g of it left?

Answer 1

The weight of the hamburger is 160g after two bites.

Each bite takes away 20% of the weight of the burger, so we'll divide the initial weight by a percentage to find the weight before the bite.

The starting weight is 160g. Because 20% of the weight was removed from a bite, we'll divide this weight by the percentage of the burger remaining after the bite:

$100 - 20 = 80$

80% of the burger is left after a bite. Convert this fraction into a decimal by dividing by 100:

$80 \div 100 = 0.8$

Divide the initial weight by this decimal:

$160 \div 0.8 = 200$

The weight of the burger before the second bite was 200.

We'll do the same procedure for the first bite. The initial weight is 200, and there is 80% of the burger remaining after the first bite. Because 80% is 0.8 in decimal form, divide 200 by 0.8:

$200 \div 0.8 = 250$

The starting weight of the burger before the bites was 250 grams.