The least whole number which when subtracted from both the terms of the ratio 6 : 7 to give a ratio less than 16 : 21, is  Select:	A) 3	B) 4	C) 5	D) 6	E) 7

Rationale: "explanation : let x is subtracted . then , ( 6 − x ) / ( 7 − x ) < 16 / 21 21 ( 6 — x ) < 16 ( 7 — x ) = > 5 x > 14 = x > 2.8 least such number is 3 option a"
Answer: A