Let's say Bailey takes "b" days to paint it.
and Andrew takes "a" days to paint the same house.
now, Andrew is 6 times faster than Bailey, therefore, if Andrew takes "a" days to do it, Bailey takes then "6a" days, or b = 6a.
now, the year they worked together, they finished it in 7 days.
so, after 1 day then, they have only done 1/7 of the whole work.
and Andrew for one day, has done 1/a of the house, whilst Bailey has done 1/b of the house or 1/(6a).

24 because 12 + 12 = 24 and and CD = DB
CB = CD + CB = 24 the triange ADC and ADB are equal
13-3/2 you need to make a common denominator, so
26/2-3/2 then subtract the numerators, the denominator remains.
23/2 now simplify the fraction
11½ this is because 22/2+1/2=23/2, and 22/2=11, so 11+1/2 or 11½
First, you multiply 600 and .20 to find 20% of 600 rupees, which is 120 rupees. Second, you subtract the 20%, (120 rupees) from 600 rupees, which is 480 rupees. After that, you have the original selling price of 480 rupees that the man purchased the article for, but the question is stating that he gained 15% of the original sales price. So, you multiply 480 and .15 to find 15% of 480 rupees, which is 72. However, he GAINED more money than what he payed for the article so you add 72 rupees to 480 rupees to get 552 rupees. In conclusion, the man sells the article for 552 rupees.