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teresachung323

P6 Mathematics

Question post on Wed, 04/09/2019 9:06pm

Anyone can help

Answer

Adwin · Answer 1 · Post on Thu, 05/09/2019 12:11am

a) Tank X gains 1200cm³ and Tank Y gain 1800cm³every minute.

Since their respective base areas are (20 x 15 = 300cm³) and (20 x 18 = 360cm³) respectively, this means they will gain (1200 / 300 = 4 cm) and (1800 / 360 = 5 cm) respectively every minute.

Therefore, Tank Y will gain 1 more cm than Tank X every minute. Since Tank X already has 8 cm at the start, this means Tank Y only needs (1 x 8 = 8 min) to overcome that 8 cm lead.

Time	Height in Tank X	Height in Tank Y
0 min	8 cm	0 cm
1 min	12	5
2 min	16	10
3 min	20	15
4 min	24	20
5 min	28	25
6 min	32	30
7 min	36	35
8 min	40	40

b) Tank X gains 1200cm³ and Tank Y gain 1800 cm³every minute.

This means that Tank Y gains (1800 cm³ – 1200 cm³ = 600 cm³) more than Tank X every minute.

Since Tank X already has (15 x 20 x 8 = 2400 cm³) of water at the start, this means that Tank Y only needs (2400 cm³ / 600 cm³ = 4 min) to overcome that 2400 cm³ lead.

Time	Vol in Tank X	Vol in Tank Y
0 min	2400	0
1 min	3600	1800
2 min	4800	3600
3 min	6000	5400
4 min	7200	7200