Casey wants to paint her 10 toenails + 10 fingernails = 20 nails in total. First she wants to do a base coat which takes 20 minutes to apply + 20 minutes to dry = 40 minutes total for the first coat. It will take the same amount of time to do a coat of paint and let it dry and to do a coat of glitter and let it dry, 40 minutes x 3 different coats = 120 minutes total to paint her toenails and fingernails.
This justifies what answer for what question? Q & A:
Casey wants to decorate her toenails and fingernails. First, she wants to do a base coat on each nail, then a coat of paint and finally a coat of glitter on every nail. It takes 20 minutes to apply each coat and 20 minutes for each coat to dry before applying the next one. Assuming Casey's nails will be done when all coats have been applied and dried, how many minutes will it take her to finish decorating her fingernails and toenails?
120