Maths -Simple questions

bonkysleuth SG

The temperature of a city on a particular day at noon is 24 deg celsius. By 2230, the temperature has fallen to -6 deg celsius. Find the temperature of the city at 1900, assuming that the temperature falls at a steady rate.

The answer's 4 degree celsius. THANKS EVERYONE!

dj woody SG

since noon is 1200 hours

so tt means from 1200-2230 (10.5 hours), temperature fall by 24-(-6) degrees [ -(-) = + ]
=30 degrees

so for every 0.5 hrs, temp fall by (30/(10.5x2))[half hours] (rate)

= 30/21

= 10/7 degrees [ rate found ]

Time difference between 1900 and 1200 = 7 hours.

Since fall by steady rate, temp at 1900 = 24- [(7x2)x 10/7) degrees

= 24 - 140/7 degrees

= 24 - 20 degrees

= 4 degrees.

d3sT1nY SG

1200H - 24 degree C

2230H - -6 degree C

So change in temperature = 24 - (-6) = 30

Change in the time is 2230H - 1200H = 10 hours 30 minutes

Therefore rate of change of temperature = 30 / 10.5 = 2.857 degree C per hour

So at 1900H is 7 hours away from 1200H = 24 - (7)(2.857) = 24 - 20 = 4 degree C

Best if you leave the 2.857 as fraction. Lol.

d3sT1nY SG

since noon is 1200 hours

so tt means from 1200-2230 (10.5 hours), temperature fall by 24-(-6) degrees [ -(-) = + ]
=30 degrees

so for every 0.5 hrs, temp fall by (30/(10.5x2))[half hours] (rate)

= 30/21

= 10/7 degrees [ rate found ]

Time difference between 1900 and 1200 = 7 hours.

Since fall by steady rate, temp at 1900 = 24- [(7x2)x 10/7) degrees

= 24 - 140/7 degrees

= 24 - 20 degrees

= 4 degrees.

Lol. Slower than you by 1 minute. =X

bonkysleuth SG

since noon is 1200 hours

so tt means from 1200-2230 (10.5 hours), temperature fall by 24-(-6) degrees [ -(-) = + ]
=30 degrees

so for every 0.5 hrs, temp fall by (30/(10.5x2))[half hours] (rate)

= 30/21

= 10/7 degrees [ rate found ]

Time difference between 1900 and 1200 = 7 hours.

Since fall by steady rate, temp at 1900 = 24- [(7x2)x 10/7) degrees

= 24 - 140/7 degrees

= 24 - 20 degrees

= 4 degrees.

Oh, so the information given is time in hours! Hah! I thought it was referring to the year. Damn, no wonder I thought there was something missing in the question.

thanks to d3sT1nY and dj woody !