The ratio of boys to girls at a movie is 4:7 If there are 21 girls, How many boys are there

Tom can paint the fence in 12 hours, but if he works together with a friend they can finish the job in 8 hours. how long would it take for his friend to paint this fence alone?

Acompany had forty one employees and ordered nine hundred eighty uniforms for them. if they wanted to give each employees the same number of uniforms, how many more uniforms should they order so they don't have any extra

Atown recently dismissed 5 employees in order to meet their new budget reductions. the town had 5 employees over 50 years of age and 19 under 50. if the dismissed employees were selected at random, what is the probability that exactly 2 employees were over 50? express your answer as a fraction or a decimal number rounded to four decimal places.