Ten large marbles weigh as much as 14 small marbles. How many large marbles weigh as much as 35 small marbles?

Sagot :

To get the answer we can use proportion
10 large ------------- 14 small
x large -------------- 35 small
crossmultiply
10*35=x*14
350=14x            /:14
350:14=14x:14
25=x-its the answer
10 is 14 marbles
so 5 is 7 marbles
now 10 is 14 marbles
        20 is 28 marbles
       we got how many is 28 marbles
we know 7 marbles is 5
we need more tahn 7
7 marbles is 5
we have 20
25 is 35 marbles
answer is 25