If I say keep a square root real. How would you answer this?

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.

Acomputer store bought a program at a cost of $10 and sold it for $13. find the percent markup

Question 14 (1 point) larry deposits $15 a week into a savings account. his balance in his savings account grows by a constant percent rate.