remember that when you have a divided fraction, you can change de numerator and denominator so your fractions be like this:
4/10 * 25/1 = 100/10
10*1
100/10= 10
this happens because when you have a fraction that is being divided, it's also like you are cross multiplying, just like the resolution upwards, then you get 100 divided by 10, which is 10.
