Let the number of mango trees and orange trees be 7a and be 9a.
If more 5 tress of each type were planted, their numbers would be 7a+5:9a+5
Given, the ratio of 7a+5:9a+5 is equal to 27:34
⇒7a+5:9a+5=27:34
⇒7a+59a+5=2734
Om cross multiplying, we have
238a+170=243a+135
35=5a
a=7
Let the number of mango trees and orange trees are 7×7=49 and be 9×7=63 respectively.