Amotorcycle shop maintains an inventory of four times as many new bikes as used bikes. if there are 64 new bikes, how many used bikes are now in stock

Well u would do 64 divided by 4, because there are 4 times as many new bikes as used ones. 
the answer is 16 used bikes 

I’m guessing that the answer is c, but i’m not sure which grid is being talked about. since 5x5= 25 and 3x3= 9 (which there are no answers for). a is not right because while the ratio is the same, 6/25= 0.24 which is equal to 24% not 30%.

Okay so for every triangle has three angles that always add up to 180 degrees. and to tell the difference between whether they are secure, right or obtuse is that acute: has one angle that is less than 90 degrees. right triangle means there is at least one angle that is exactly 90 degrees. and an obtuse angle has an angle that is bigger than 180 degrees. i’ll do #13 as an example: 13. 40 and 50 so if every triangle has 180 degrees 40+50= 90 degrees then180-90= 90 degrees so the third angle is 90 degrees and because this triangle has a 90 degree angle it means it is a right triangle