Let weight of a and b are 3x and 5x respectively. then sum of their weight =8x New weight of a=1.2(3x)=3.6x and new total weight =1.1(8x)=132 1.1(8x)=132⇒x=15 Now, old weight of b=5x=75kg New weight of a=3.6×15=54kg So new weight of b=132−54=78 Hence, percentage increment in weight of b=