Pls do q no. 5
2nd one
Answers
what's the answer???
Answer: Bigger pipe = 5 mins
Smaller pipe = 8 mins.
Step-by-step explanation:
Two taps together == 3 1/13 min = 40/13 mins === 1 tank
In 1 min == 1/(40/13) part = 13/40 part of tank
Let the bigger pipe take 'X' mins to fill the tank (alone)
Smaller pipe = X + 3 mins
Bigger pipe in 1 min fill : 1/X part of the tank
Smaller pipe in 1 min fill : 1/X+3 part of the tank
Together in 1 min :
1/X + 1/X+3 = 13/40
X+3+X/(X*[X+3]) = 13/40 [took LCM at LHS]
2X + 3 / (X²+3X) = 13/40
40 [2X + 3] = 13 [X²+3X]
80X + 120 = 13X² + 39 X
13X² - 41X - 120 = 0 [39X - 80X = -41X]
sum = -41
product =13*-120=-1560
The numbers are -65,24
13X² - 65X + 24X - 120 = 0
13X[X-5] + 24[X-5] = 0
[13X+24][X-5] = 0
X-5 = 0
X = 5
Hence bigger pipe = X = 5 minutes
Smaller pipe = X+3 = 8 minutes
Additional info:
How we got the numbers -64,21
product = 1560
1560 = 156 * 10 = 12 * 13 * 10 = 4*3*13*2*5 = 4*3*2 * 13*5 = 24*65
Hence, -65+24 = -41 && -65*24=-1560