For a given angle of projection if the maximum height reached by a projectile is increased by 10% the horizontal range will

h∝u2 dhh=2(duu)10%=2duuduu=5%Also R∝u2dRR=2(duu)=2(5%)=10%Also, we observe that R and H both are proportional to u2, so R also gets an increment of 10%.