Bob the builder is making 480 kg of concrete mix concrete is made by mixing cement sand and gravel in the ratio 1: 3: 4 how much does he need

see the explanation

Step-by-step explanation:

Let

x ---> kilograms of cement needed

y ----> kilograms of sand needed

z ----> kilograms of gravel needed

we know that

---->

Divide 480 by 8

----> scale factor

Multiply the scale factor by the ratio

Find out the kilograms of cement needed

Find out the kilograms of sand needed

Find out the kilograms of gravel needed

to find the unit price, we must figure out the cost of one item (in this case one dish towel).   to do this, we divide the total price ($7.92) by the number of items bought (for this problem it is 8, because there are eight dish towels in one pack).  

$7.92/8 = $0.99

therefore, the unit price, or the price of one dish towel, is $0.99.

hope this !