Question

2mangoea and 5apple in rate 40ruppes how many rate if 8mangoes and 20 apple ...plz ans

Answer 1

OK let's have a price of x rupees for a mango and a price of y rupees for an apple
so, what is given is
2x + 5y = 40
let's see what we get if we multiply this wholly by 4
$4(2x + 5y) = 4 \times 2x + 4 \times 5y = 8x + 20y$
that is exactly the price of 8 mangoes and 20 apples
so,
$2x + 4y = 40 \\ this \: implies \: that \\ 4(2x + 5y) = 4 \times 40 = 160$
therefore,
the price of 8 mangoes and 20 apples is rupees 160