Sammi had 19 marbles and bob gave him 1/7 of his marbles now Sammi has 27 how many marbles did bob have originally? pls help

The mathematical expression 9€ t means

4. a spring scale is constructed so that each 0.10-n increment is separated by 0.50 cm. what spring constant is necessary for the scale to be accurate? -1.0n/cm -0.10n/cm -9.8 n/cm -0.20n/cm

You love to play soccer! you make a shot at the net 8 times during a game! of those 8 attempts, you score twice. what percent of the time did you score?