Question

If a can type 5 pages in 9 minutes and b can type 6 pages in 11 minutes then the time taken to type 218 pages, if both a and b work together, is :

Answer 1

Susan, does one page:

(5/10)=1/2

Mary, does one page:

(10/5)=2

so, both do :

net-work: (2+1/2)=5/2

thus ,

1 minute work done: 5/2

so,,in 30-minutes :  30*(5/2)=75 pages