Common factors are 5 and 15 and 3
Answer:
D. x + 10 pence
Step-by-step explanation:
Since the pen costs 10 pence more than the ruler, we need to add 10 to x.
Answer:
The differential equation which describes the mixing process is
.
Step-by-step explanation:
The mixing process within the tank is modelled after the Principle of Mass Conservation, which states that:

Physically speaking, mass flow of salt is equal to the product of volume flow of water and salt concentration. Then:

Given that
,
,
,
,
and
, the differential equation that describes the system is:



Truncated . . . 28.45 . / / / Rounded . . . 28.46 .