Making equation let A for Apple, B for Banana and G for Grape,
A + G + 2B = 210
ans condition is B =< G =< A
range is [ 30, 90 ]
So total possible solutions which staisfies the condition and equation both will be 6
(1) A = 90 , B = 30 , G = 60
(2) A = 80 , B = 30 , G = 70
(3) A = 90 , B = 40 , G = 40
(4) A = 80 , B = 40 , G = 50
(5) A = 70 , B = 40 , G = 60
(6) A = 60 , B = 50 , G = 50