total num of pupiles in 3 grades of scholl is 333 . the no of pupiles in grades 1 and 2 are un 3:5 ratio and 2 and 3 grades are 7:11 ratio .what is the strength of class that has highest no of pupils	Choose the correct choice from the following options
A) 145 B) 155 C) 165 D) 175 E) 185

Rationale: ratio g 1 : g 2 = 3 : 5 and g 2 : g 3 = 7 : 11 so g 1 : g 2 : g 3 = 21 : 35 : 55 let the strength of three classes are 21 x , 35 x and 55 x respectively , then 21 x + 35 x + 55 x = 333 = > 111 x = 333 or x = 3 so strength of the class with highest number of pupils = 55 x = 55 * 3 = 165 answer : c
Answer: C