Question

I've joined this gaming app where you make money and the way you do that is by receiving these virtual gifts called "diamonds" which can convert into money. The minimum amount of money you're able to convert your diamonds into is $200 and you need a minimum of 40,000 diamonds to do so. I'm curious to know how many diamonds is equlivent to $20.
If 40,000 diamonds is equivalent to $200, how many diamonds is equlivent to $20?

Thanks.

Answer 1

First you need to find out how many diamonds are equivalent to $1.
$x = \frac{40000}{200} \\ x = 200$
$1 is equivalent to 200 diamonds, so you just multiply 200 times 20 to see how many diamonds are equivalent to $20
$x = 200 \times 20 \\ x = 4000$
$20 is equivalent to 4,000 diamonds

Answer 2

It is easy to see that 20 is 200 divided by 10, so if you want one tenth of the dollar, you'll need one tenth of the diamonds.

Otherwise, simply write the proportion

$200:40000 = 20:x$

and solve for x:

$x = \dfrac{40000\cdot 20}{200} = 4000$

which is indeed one tenth of 40000