An apple and a pear weigh 280 grams, an apple and an orange weigh 200 grams, a pear and an orange weigh 220 grams

An apple and a pear weigh 280 grams, an apple and an orange weigh 200 grams, a pear and an orange weigh 220 grams

(280 + 200 + 220) △ 2 = total weight of an apple, an orange and a pear
Total weight - 280 = orange
Total weight - 200 = pear
Total weight - 220 = apple
The answer is calculated by yourself!
This problem is very simple. I can do it in the third grade

An apple and a pear weigh 270 grams, and an apple and two pears weigh 420 grams. How many grams do the pears and apples weigh?

Pear 420-270 = 150g
Apple 270-150 = 120g

Three apples are equal to the weight of four peaches, three pears are equal to the weight of five peaches, one apple is 150g, how many grams are two pears heavier than two peaches

3a=4b b=3/4a
3c=5b
a=150
b=450/4
c=5/3*450/4=2250/12
2(c-b)=150
It weighs 150 grams

On the balance, three pears are equal to four peaches, and three apples are equal to five peaches. How many peaches are an apple and a pear

1 pear = 4 / 3 peach
1 apple = 5 / 3 peaches
1 pear + 1 apple = (4 / 3 + 5 / 3) peaches = 3 peaches