Find the answer of 400% of 90

Ican figure out 20 shares multiply by $117.98 =2359.6920 shares multiply by $124.32=2486.40then take 40 shares multiply by $128.48=5139.20after that i'm lost any be greatly appreciated.

Una caja de galletas contiene 16 paquetes y cada una de estas tiene 12 galletas y se quieren repartir entre 6 niños ¿de cuantas galletas le toca a cada niño?

Weekly wages at a certain factory are normally distributed with a mean of $400 and a standard deviation of $50. find the probability that a worker selected at random makes between $450 and $500