The average age of 80 girls is 15 years and the average age of x boys is 20 years. If the average age of all is 16 years, find the number of boys (x).
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0
Answer:
15.25yrs
Step-by-step explanation:
Total ages of 80 boys = 15 x 80 = 1200 yrs.
Total age of 16 boys = 15 x 16 = 240 yrs
Total age of 25 boys = 14 x 25 = 350 yrs.
Average age of remaining boys = 1200 - (240+350) / 80 - (25+15) = 610/41 = 15.25 yrs.
Answered by
0
Answer:
let the total sum of girls age = a
=>a/80 = 15
=>a=120
let the total sum of boys age = b
=>b/x=20
=>b=20x
total average is
(a+b)/(80+x) = 16
=>120+20x=128+16x
=>4x=8
=>x=2
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