Question
39. ( quad(3) because 60 % ) of ( A=75 % ) of ( B ) ( Rightarrow quad frac{60 times A}{100}=frac{75 times B}{100} )
( Rightarrow quad 4 A=5 B )
( Rightarrow quad B=frac{4}{5} A=frac{4 times 20}{5 times 20} times A )
But ( B=x % ) of ( A )
( x=80 )

39. If 60% of A's income is equal to 75% of B's income, then B's income is equal to x% of A's income. The value of x is (1) 70 (2) 60 (3) 80 (4) 90
Solution
