Working together Coby and Stills can autograph 95 of their f

Working together, Coby and Stills can autograph 95 of their fans\' program in 25 minutes. Working alone, Coby can sign 5 programs in 6 minutes. How long would it take Stills to sign 95 fans\' programs if he worked alone?

Solution

let rate at which coby can alone autograph =x , rate at which stills can alone autograph =y

x=5_/6 , x+y =95_/25

=>(5_/6)+y =(95_/25)

=>y =(95_/25)-(5_/6)

=>y =(89_/30)

alone stills can autograph at (89_/30) fans\' programs per minute

time taken by stills alone to autograph 95 fans\' programs =95_/(89/30)

time taken by stills alone to autograph 95 fans\' programs =95*30_/89

time taken by stills alone to autograph 95 fans\' programs =32 minutes