Snow Problem

[Dee-M-See]

It snowed for five days and 155 mm was recorded

Each day there was twice as much as the previous day

How much snow fell on the fourth day?.

[smouse]

40
5 10 20 40 80

[Aquagility]

x+2x+4x+8x+16x=155

So 31x=155

So x=31

So, as Smouse says, 4th day has 40mm.

[Aquagility]

Sorry, senior moment, last line should be x=5.

[crofter]

If you want a formulaic approach, suppose it snows an amount X mm on the first day, then over the next four days the amounts of snow will be 2X, 4X, 8X and 16X totalling 31X mm over the five days.

So 31X = 155 => X = 155/31 = 5.

On day four, this is 8X = 40 mm (as smouse says)

[crofter]

Sorry Aq, I didn't know that you were also on to this! c

[Dee-M-See]

Thank you very much for your prompt replys and also how you work it out

[Aquagility]

No problem, Crofter. Great minds, etc.