A computer is on sale from two different internet sites. site a sells it for $1,250 plus free shipping. they offer a 20% discount with an internet coupon. site b sells the same computer for $1,000 plus a $20 shipping charge

Site a:

$1250 and 20% discount.

Since a 20% discount is given, the price is 100% - 20% = 80% of the price.

Price = 80% of 1250 = (80/100) * 1250 = 0.8*1250 = 1000

Price = $1000

Site b: $1000 + $20 = $1020.

Hence site a is cheaper than site b.