word problem

Question

Over the last three evenings, Keiko received a total of 105 phone calls at the call center. The second evening, she received 5 more calls than the first evening. The third evening, she received 3 times as many calls as the first evening. How many phone calls did she receive each evening? please help and thanks

Answer 1

x = calls 1st evening

y = calls 2nd evening

z = calls 3rd evening

 

x + y + z = 105     {equation 1}

y = x+5                {equation 2}

z = 3x                   {equation 3}

 

Substitute x+5 for y and 3x for z in 1st equation

 

x + x + 5 + 3x = 105

5x = 100

x = 20 calls first evening

 

From here just use 2nd and 3rd equations to get number of calls

for the 2nd and 3rd evenings.