Aweight of 15 ounces stretches a spring 10 inches. a weight of 24 ounces stretches the same spring 16 inches. how many inches does the spring stretch per ounce of additional weight?

At dinner, 2/5 of the people had fish and 1/3 had chicken. if everyone else had lamb, what fraction of the people had lamb? and if 40 people had lamb , calculate the total number of people at the dinner.

The hawaiian alphabet has 12 letters. how many permutations are posible for each number of letters?

If np3 /nc2 = 6, find the value of n