Write these pairs of fractions as a pair with a common denominator

3/10 2/5. 1/3 3/4

10 * 5 * 4= 200

60/200

400/200

50/200

you multiply all the denominator then 

divide the result ( 200 here) by each denominator to get the nominator factor and nominator factor * nominator = new nominator

for ex

200 / 10 = 20

so 20 * 3/200  = 60 /200 and so on

No a triangle cannot be formed because when you add the two smallest number together (which would be 11) the have to be bigger than the number it is "against" ( which would be 12)