Question

in a farm,there are 250 trees,125 of them are mangoes tree,75 are coconut trees are rest plums trees find the ratio of mangoes tree to coconut tree

Answer 1

Whenever it is not explicity mentioned that fruit and distint, We take them as identical. 0 or more orange can be selected from 4 identical oranges in (4+1)=5 ways. 0 or more apples can be selected from 5 identical apples in (5+1)=6 ways.

0 or more mangoes can be selected from 6 identical mangoes in 7 ways.

∴ Total no. of ways in which all of three types of fruits can be selected (the no. of any type of fruits may also be 0),

5×6×7=210,

But in these 20 selection, there is one selection where all fruits are 0, hence we reduce 1 selection.

∴ the required no. =210−1=209