a customer buys some apples, mangos and oranges which total comes exactly 100 fruits
the cost of one apple is 5 Rs.
the cost of one mango is 2 Rs.
and four oranges cost 1 Rupee.
the total amount he pays also equal to 100 Rs.
then how many apples, mango and oranges did he buy?
how these kinds of problems solved mathematically?