# Two Water Taps Together Can Fill a Tank in 1 7 8 Hours. the Tap with Longer Diameter Takes 2 Hours Less than the Tap with a Smaller One to Fill the Tank Separately. - Mathematics

Sum

Two water taps together can fill a tank in 1(7)/(8)  hours. The tap with longer diameter takes 2 hours less than the tap with a smaller one to fill the tank separately. Find the time in which each tap can fill the tank separately.

#### Solution

Let the first tap takes x hours to completely fill tank
⇒ Second tap will take 2 hours less
⇒ According to question

(1)/("x") + (1)/("x" -2) = (8)/(15)

("x"-2+"x")/("x"("x"-2)) = (8)/(15)

(2"x"-2)/("x"("x"-2)) = (18)/(15)

((2"x"-1))/("x"("x"-2)) = (18)/(15)

15 ("x"-1) = 4"x" ("x" -2)

15"x" - 15 = 4"x"^2 - 8"x"

4"x"^2 - 23"x" + 15 = 0

4"x"^2 - 20"x" - 3"x" + 15 = 0

4"x"("x" - 5) - 3 ("x" -5) = 0

("x" - 5) (4"x" - 3) = 0

"x" = 5 or (3)/(4)

Since (3)/(4) - 2 = "Negative time" (3)/(4) is not possible.
Which is not possible
⇒ x = 5
Rate of 1st pipe = 5 hours
Rate of 2nd pipe = 5 - 2 = 3hours

Concept: Quadratic Equations Examples and Solutions
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