If you plot the temperatures of the two cities on a number line, you see that the temperature for City R is plotted to the right of the temperature for City S. This means the temperature of City S is less than that of City R.
The ratio is 4:3:1 let the ratio be 4x:3x:x according to the question,4x+3x+x=40 8x=40 x=5 therefore amount of gravel=x*4=5*4=20 amount of sand=5*3=15 amount of cement=5*1=5