CBSE Class 12-science Answered

let no. of  units of A wihch are sold = a , where 100a300

and no. of units of B which are sold = b , where 100b250

so profit p = 5a+4b................(1)

since labour hours are fixed so we have 10a+8b=4000 or 5a+4b = 2000........(2)

since from (2) 5a+4b (which is also equals to profit ) has a fixed value independent of a and b

so profit will be fixed independent of a and b

if we choose a such that it lies between 100 and 300 then we can find b using (2).

for example if we choose a= 200 then b will be 250 which is valid.

here we have to take care that values of a and b lies within the range specified.