​ Help pls

That is an awful lot of Q's for one post !

1. Circumference of wheel = pi * d   (inches)       distance travelled for each wheel is pi * d * rpm  (inches per min)

        26 inch wheel      pi * 26 x 200 =  ~~16336.3  inches per minute

    YOU do the 20 inch wheel

2.This is a conversion from in/min   to mile/hr

    26 inch wheel       16336.3 in / min   x  1 ft / 12 in  x  1 mile / 5280 ft    x   60 min / hr  =   15.5 m/hr

    YOU do the 20 inch one

5  is an easy one     200 r  /min  x  1 min / 60 sec   =               r/sec      You can write the sentence .

3  pi 20 (x)  =  pi 26 (200)    solve for x   the number of RPM the 20 inch tire will need to keep up with the 26 inch tire

                                                   NOTE: SEE what the question asks when you get this answer !   DO THE WORK !

4.    200 rot/min   x  1 min /60 sec   x   2 pi   Radians  /rot  = ......     Radian/sec

'exact form'  means leave  'pi' in the naswer .....do not multiply it out (I think)      and if it results in a repeating decimal....leave the fraction intact in the answer....   cool?