One nickel weighs 5 g. Find how many nickels are in 7.0 kg of nickels

                                                                                                               there are 200 nickels in 1 kilogram of nickels

Step-by-step explanation:

For this case we must take into account the following conversion:

1Kg = 1000 g

Therefore, we can make the following rule of three:

5 grams > 1 nickel

1000 grams > x

Clearing x we have:

x = (1000/5) * (1)

x = 200 nickels

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4