Decrease and Increase in Ratio: If the no. of teachers in a college is increased from 50 to 60. Then the ratio of new staff and old staff is i.e. We say that, no. of teachers has been increased in ratio 6 : 5. In other words, no. of new staff is times the no. of old staff. Hence
Rule: To increase a no. “” we multiply by an improper fraction. Similarly to decrease a no. “” we multiply by an proper fraction. e.g. (1) Increase Rs. 20 in ratio 6 : 5 New value = e.g. (2) Decrease 56 in ratio 7 : 8 New value =
times the no. of old staff.
” we multiply 
by an improper fraction.
” we multiply 
by an proper fraction.
