Answer :
for your first one: add all of the marbles together
6+3+7= 16
your ratio is white marbles to total number of marbles. 3:16
for your second one: 1, 2, 3, 4, 5, 6
you only want the numbers less than three. 1 and 2.
you have a total of 6 numbers and two of these are less than 3. so the probability would be 4:6
for the third one: add your twos and threes
60+66= 122
your probability is 122:360
6+3+7= 16
your ratio is white marbles to total number of marbles. 3:16
for your second one: 1, 2, 3, 4, 5, 6
you only want the numbers less than three. 1 and 2.
you have a total of 6 numbers and two of these are less than 3. so the probability would be 4:6
for the third one: add your twos and threes
60+66= 122
your probability is 122:360