Help please! - Bracket Maths
Posted: Fri Jan 20, 2012 12:35 pm
In a question of this format, (a [ b ] c), should the number in middle should always be made using numbers on either side or can 'b' be made using just either a or c? And can a, b, c can be a sequence as well?
In this question,
(36 [18] 6) (24 [12] 4) (42 [ ? ] 7)
my DD worked out the answer as 21 (half of the first number or 3 times the third number is the rule according to her.) When I suggested that she should use both the numbers, she came up with the rule saying it is a sequence with 1/2 and 1/3. Is that ok?
My rule of "first number - 3 x the third number" was not very appealing to her:-((
In this question,
(36 [18] 6) (24 [12] 4) (42 [ ? ] 7)
my DD worked out the answer as 21 (half of the first number or 3 times the third number is the rule according to her.) When I suggested that she should use both the numbers, she came up with the rule saying it is a sequence with 1/2 and 1/3. Is that ok?
My rule of "first number - 3 x the third number" was not very appealing to her:-((