9.) Two water taps together can fill a tank in 75/8 hours. The tap of larger diameter takes10 hours less than the smaller one to fill the tank separately. Find the time in which each tap can separately fill the tank.
Answers
||✪✪ QUESTION ✪✪||
Two water taps together can fill a tank in 75/8 hours. The tap of larger diameter takes10 hours less than the smaller one to fill the tank separately. Find the time in which each tap can separately fill the tank. ?
|| ✰✰ ANSWER ✰✰ ||
Let us assume that, The TAP with Smaller Diameter can fill the Tank in = x hours .
So, Tap with larger Diameter will take = (x - 10) hours.
So,
→ Per hour Smaller diameter Tap fill = (1/x) litre ,
→ per hour Larger diameter tap fill = 1/(x-10) litre .
Now. , Given that, both Fill the tank in 75/8 hours.
So,
→ 1/x + 1/(x-10) = 8/75
Taking LCM,
→ (x-10 + x) / (x² -10x) = 8/75
Cross - Multiply,
→ 75(2x-10) = 8(x² - 10x)
→ 150x - 750 = 8x² - 80x
→ 8x² - 230x + 750 = 0
Dividing by 2 both sides,
→ 4x² - 115x + 375 = 0
Splitting the Middle Term now,
→ 4x²-100x-15x +375 = 0
→ 4x(x-25)-15(x-25)=0
→ (x-25)(4x-15) = 0
Putting both Equal to zero now,
→ x = 25 or (15/4) .
______________
If x= 25
Than, (x-10) = 25-10 = 15
if x = (15/4)
(x-10) = 15/4 - 10 = (15-40)/4 = -25/4.
As , Time can't be in Negative..
So, x = 25 hours...
Hence, The TAP with Smaller Diameter can fill the Tank in 25 hours and The TAP with Larger Diameter can fill the Tank in 15 hours .
Time taken by smaller tap is 25 hrs and by larger tap is 15 hrs
✎ Lets assume that the time taken by smaller tap to fill the tank is x hrs .
✎ It's given that the larger tap will fill the tank 10 hrs early . So larger tap will fill the tank in x-10 hrs .
______________________
✎ Now the volume of water filled in 1hr
By smaller tap = hrs .
By larger tap = hrs .
We are given that time taken by both taps is hrs .
✎Now we'll find volume filled by each tap in 75/8 hours .
By smaller tap = × hrs .
= × .
= .
✎ Now we know that Sum of volume filled by both taps will be equivalent to 1 .
+ . = 1
+
. = 1
x - 10 + X/ x² -10x = 8/75
(2x-10)75 = (x²-10x)8
150x - 750 = 8x² - 80x
150x + 80x = 8x² + 750
230x = 8x² + 750
8x² - 230x + 750 = 0 .
✎ Now using quadratic formula .
a = 8
b = -230
c = 750
.
.
✎ Taking positive sign .
✎ Taking negative sign
✎ Now we have two AnSwers of x . Let's find x-10
If x = 25
x- 10 = 15 hrs.
If x= 15/4
x- 10 = -25/4
As time can't be negative so time taken by larger tap is 15 hrs and by smaller tap is 25 hrs