t&w q9

[Saumyojit]

Two typist of varying skills can do a job in 6 minutes if they work together. If the first typist typed alone for 4 minutes and then the second typist typed alone for 6 minutes, they would be left with
1/5 of the whole work. How many minutes would it take the slower typist to complete the typing job working alone ?


Wa * 4min + Wb * 6 min = 4/5

(Wa + Wb) * 6 min = 1 whole work

Then?​

 

[Dr.Peterson]

Two typist of varying skills can do a job in 6 minutes if they work together. If the first typist typed alone for 4 minutes and then the second typist typed alone for 6 minutes, they would be left with
1/5 of the whole work. How many minutes would it take the slower typist to complete the typing job working alone ?

Wa * 4min + Wb * 6 min = 4/5
(Wa + Wb) * 6 min = 1 whole work

Then?

Then ... write these as equations without the units, and solve the resulting systems (e.g. by adding two equations together). Please show an attempt.

 

[Deleted member 4993]

Two typist of varying skills can do a job in 6 minutes if they work together. If the first typist typed alone for 4 minutes and then the second typist typed alone for 6 minutes, they would be left with​

1/5 of the whole work. How many minutes would it take the slower typist to complete the typing job working alone ?​

​

​

Wa * 4min + Wb * 6 min = 4/5​

​

(Wa + Wb) * 6 min = 1 whole work​

​

Then?​

Just by observation, without lifting a pencil, you should be able to tell that A will finish 1/5 (=1- 4/5) of the job in 2 minutes. And then continue (this problem should be done mentally first and then checked with paper and pencil).