Question

If 6 pipes fill a tank in 120 minutes, then 5 pipes can fill it in how many minutes​

Answer 1

144 minutes

Explanation:

here we use inverse proportion because the more pipes there are the less time is needed

the formula for inverse proportion is y = k/x

first we need to find k which is the constant

if y is the number of minutes and x is the number of pipes we can substitute these into the formula like so: 120 = k/6

to find k rearrange the formula to get k = 6 * 120 = 720

now that we have k we can substitute 720 (k) and 5 (x) into y = k/x

y = 720 / 5

y = 144

(y is the number of minutes in this case so the answer is 144 minutes)

Answer 2

It'll take 144 minutes for 5 pipes.

Explanation:

`{ \sf{6 \: pipes = 120 \: mins}} \\ { \sf{5 \: pipes = ( (6)/(5) * 120) \: mins}} \\ \\ = { \sf{144 \: mins}}`

but practically, it seems to be abnormal. if 6 pipes take 120 mins, 5 pipes must takes a time greater than 120 mins cause amount of water flowing to the tank is decreasing.

But there is a possibility that pressure of water was increased for the case of five pipes, that's why it takes a time less than 120 mins. (t < 120)