Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?

3

Step-by-step explanation:

Let system security be A, program implementation be B and platform development be C

Then:

25 = A + B + C - AB - BC - AC + ABC

where AB is system security and program implementation,

BC is program implementation and platform development,

AC is system security and platform development and

ABC is all three

So plug in the given numbers to get:

25 = 10 + 13 + 12 - AB - 5 - 4 + 2

25 = 35 - AB - 9 + 2

25 = 35 - AB - 7

AB = 35 - 7 - 25

AB = 3

days of the week

step-by-step explanation:

javier earned more money then kyle, so that won't always be a constant term, but the days of the week do not change so that term is always constant.

edit: i meant

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.