5 yuan a catty of apple, 3 yuan a catty of pear, 1 yuan 3 catty of orange, how to use 100 yuan to buy 100 catty of fruit? Who can help answer, thank you~ All three kinds of fruits~

5 yuan a catty of apple, 3 yuan a catty of pear, 1 yuan 3 catty of orange, how to use 100 yuan to buy 100 catty of fruit? Who can help answer, thank you~ All three kinds of fruits~

5 yuan per catty apple: 60 yuan - 12 catties
3 yuan / Jin pear: 12 yuan - 4 jin
One yuan 3 Jin Orange: 28 yuan - 84 Jin

I went to the supermarket to buy a total of 21kg apples and oranges, apples 3 yuan a Jin, oranges 2.5 yuan a Jin, I bought how many jin apples and oranges?

It's 27 yuan in total. Otherwise, it can't be calculated. It should be 3x + 2.5Y = 21. It shouldn't be an integer of two Jin apples and six Jin oranges

Xiao Hong bought 5 kg of apples and oranges, which cost 17 yuan. It is known that apples cost 4 yuan per kg and oranges 3 yuan per kg

I bought x kilograms of apples
4x+3(5-x)=17
4x+15-3x=17
x=2
5-x=3
Spent 2 * 4 = 8 yuan to buy apples
I spent 3 * 3 = 9 yuan on oranges

There are three piles of apples. The first pile is 2 / 5 tons, 1 / 8 tons less than the second pile. The third pile is 12.5% less than the second pile. How many tons are there in the third pile?

The second pile includes:
2 / 5 + 1 / 8 = 0.4 + 0.125 = 0.525 (ton)
The third pile includes:
0.525 × (1-12.5%) = 0.459375 (ton)