RRB Government Jobs Exams

22) The present ratio of students and teachers at a certain school is 30 to 1. If the student enrolment is to increase by 50 students and number of teachers by 5, the ratio of teachers would then be 25 to 1. Find the present number of teachers.
a) 15
b) 8
c) 10
d) 15

Read Solution (Total 2)

s/t=30/1
s=30t;
s+50/t+5=25/1
s+50=25t+125
30t+50=25t+125;(bcz s=30t)
5t=75;
t=15(ans)
11 years agoHelpfull: Yes(1) No(0)

(30x+50)/(x+5)= 25/1
30x+50=25x+125
x=15
10 years agoHelpfull: Yes(1) No(0)

RRB Other Question

16) If 75% of the class answered the first question of the test correctly, 55% answered the second question correctly and 20% answered neither of the questions correctly, what % answered both correctly?
a) 10
b) 20
c) 50
d) 65
A students average score in 10 tests is 78. What must be the students score on a 5th test for the overall average score to become 80?

a) 80
b) 84
c) 82
d) 88