The number of students enrolled at school XX this year is 7 percent more than it was last year. The number of students enrolled at school YY this year is 3 percent more than it was last year. If school XX grew by 40 more students than school YY did, and if there were 4000 total enrolled students last year at both schools, how many students were enrolled at school YY last year? Choose the correct option:
A) 480 B) 1600 C) 1920 D) 2080 E) 2400

Rationale: given info : no . of students enrolled in school x is = 7 % more than previous year ' s strength = 7 x / 100 no . of students enrolled in school y is = 3 % more than previous year ' s strength = 3 y / 100 given that ` ` this year ' ' school x have 40 students more than school y . so the increase in strength can be written as 7 x / 100 = 40 + 3 y / 100 7 x = 4000 + 3 y . . . . . . . . . . . . . . . . . . . . ( 1 ) and total students on previous year are x + y = 4000 . . . . . . . . . . . . . . . . . . . . . . ( 2 ) equating & solving we get , y = 2400 ans is e
Answer: E