Question

over the last 3 evenings 85 phone calls were received. the second evening she received 5 fewer calls than the first evening.The third evening she received 4 times as many calls how many did she receive each evening

Answer 1

a =20, b =15, c= 60

1) Writing this we have

1st evening: a

2nd evening: b

3rd evening: c

a +b+ c = 85

b=5 -a

c=4a

2) So rewriting this out as an expression we have:

a + b+ c = 85 Plug into that in terms of "a"

a + 5-a + 4a = 85 Combine like terms

4a +5 = 85 subtract 5 from both sides

4a = 80 Divide both sides by 4

a = 20

2.2) Plug into each formula:

b =a -5

b = 20 -5

b = 15

20+15 + c = 85 Add them up

35 +c = 85 Subtract 35 from both sides

c = 85 -35

c= 60

Or we could have done it:

c = 4b

c= 4* 15

c= 60

3) Hence, the answer is a =20, b =15, c= 60