You could obviously test numbers and solve it, which is actually reasonably fast or, you could deduce that 1188 = 2*2*3*3*3*11
Obviously one of the numbers has to be divisible by 11. So if you look at the choices and see for x = 84, y = 156 and neither are divisible by 11, then you could look at x = 96, y = 144, and neither are divisible by 11. So then, you've killed three choices already. You look at 108 and 132. 132 is divisible by 11. Hence 108 is the answer. Or of course you could use the fact that HCF * LCM = x * y
or in this case 14256 = x(240 - x)
you can use the following formula; ((-b (+ or -))sqrt(b^2 - 4ac))/2a
from where you can get both values of x and the smaller one is the answer.
Obviously one of the numbers has to be divisible by 11. So if you look at the choices and see for x = 84, y = 156 and neither are divisible by 11, then you could look at x = 96, y = 144, and neither are divisible by 11. So then, you've killed three choices already. You look at 108 and 132. 132 is divisible by 11. Hence 108 is the answer. Or of course you could use the fact that HCF * LCM = x * y
or in this case 14256 = x(240 - x)
you can use the following formula; ((-b (+ or -))sqrt(b^2 - 4ac))/2a
from where you can get both values of x and the smaller one is the answer.
) difficulty!
My 1st Post ....!!!
