person usually spent rs. 48 to buy groundnuts for roasting and resale. on one occasion he could buy 1.5 kg of groundnuts less for rs. 48 as the price has gone up by 25%. what was the earlier price of groundnut per

25%===1/4 4-----5 1-----1.5 5---7.5 48/7.5==6.40rs

If a and b are positive integers such that 3 is a root of the equation ax?-12x+b=0, how many ordered pairs (a,b) exist?

sanchit we have to find positive integers and 0 is not a positive integer so there will be 11 cases only

3a + b = 36 a=0, b=36 a=1, b=33 . . . . a=12, b = 0 so total 13 cases :)