The enrolment for this school year is 2340 if 1/6 are sophomores and 1/4 are seniors how many are freshmen and juniors?

of 2340
=  × 2340
= 585 (this is the total number of seniors)

of 2340
=  × 2340
= 390 (this is the total number of sophomores)

585 + 390 = 975 (this is the total of sophomores and seniors)

Therefore the number of freshmen & juniors must be
2340 - 975
= 1365

Dis a correct answer