Well, basically, what you have to do is compare. So
250 bricks= 20 feet
y bricks= 30 feet
I represented the unknown with y, anyway, you have to cross and multiply. So 30 multiplies 250 and 20 multiplies y. So;
7500=20y
Next, you have to divide the both sides by 20. That will be;
7500/20=20y/20
375=y
y=375
So it takes 375 bricks to build upto 30 feet. Hope i helped.
