If a : b : c = 4 : 7 : 9 and b : c : d = 28 : 36 : 21, then a : b : c : d is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 16 : 28 : 36 : 21
a : b : c = 4 : 7 : 9----(1)
b : c : d = 28 : 36 : 21-------(2)
Make b & c same in both:
b : c in first = 7 : 9
b : c in second = 28 : 36
LCM method:
Make 7 → 28 ⇒ multiply first ratio by 4:
a : b : c = 4 × 4 : 7 × 4 : 9 × 4 = 16 : 28 : 36
Now d = 21 from second ratio:
a : b : c : d = 16 : 28 : 36 : 21