Fractions with the same denominator?

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.

One side of a rectangle is 7 feet shorter than seven times the other side. find the length of the shorter side if we also know that the perimeter of the rectangle is 306 feet.

Louise measured the perimeter of her rectangular scrapbook to be 154 cm. if the scrapbook is 45 cm wide, how long is the scrapbook?