The expected answer is

      Range R = u  (2H)1/2
                                 (g)         OR 
         H = R2g
               2u2

         = 252 X 10
               2 x 42
              = 195.3m
      ALTERNATIVELY
       Time t = distance =  25
                         speed        4
                                   = 6.25s
      s = ut  +1∕2 gt2   OR  s = ½ gt2
      = ½   x  10  x 6.252

This question, also on projectile motion, was very popular. It was satisfactorily handled by most of the candidates. However, some candidates could not apply the relation R = u     √2H          to determine H.
                                                                                                                                            g

Majority of the candidates used the alternative method. They were able to obtain the time of fall, t as the ratio of distance to speed and proceeded to obtain the height H from the relation H = ½ gt2 , '