Two equal circles intersect such that each passes through the centre of the other. If the length of the common chord of the circles is 10?3 cm, then what is the diameter of the circle?

Correct Answer: 6/?+4

Explanation:

Correct Answer: 4

Explanation:

Let 2+?2+?2..... = t
2+?t = t
t - 2 = ?t
t = 4

Correct Answer: a/b = c/d

Explanation:

(4a+7b)(4c-7d) = (4a-7b)(4c+7d)

(4a+7b)/(4a-7b) = (4c+7d)/(4c-7d)

Using componendo and dividendo

(4a+7b)+(4a-7b) / (4a+7b)-(4a-7b)

= (4c+7d)+(4c-7d) / (4c+7d)-(4c-7d)

Or 8a/14b = 8c/14d

Or a/b = c/d

Correct Answer: xy/x+Y

Explanation:

Correct Answer: Each fraction is equal to 1/2 or -1

Explanation:

a/(b+c) = b/(c+a) = c/(a+b)

Taking reciprocal and adding 1 to each ratio we get;

(b+c)/a + 1 = b/(c+a) + 1 = c/(a+b) + 1

Or (a+b+c)/a = (a+b+c)/b = (a+b+c)/c

So this can only be equal when a=b=c or a+b+c = 0

When a=b=c we get

a/(b+c)= ½When a+b+c = 0 we get

b+c = -a

So a/(b+c) = -1

So the ratios are ½ or -1

Correct Answer: 2m ?m^2/n

Explanation:

Mean of m observations is n

Mean of n-m observations is m

So total = nm+ (n-m)m

Total observations = n

Mean = Total / Total observations = (2mn-m^2)/n = 2m ?m^2/n

 

Correct Answer: 1

Correct Answer: 5?3

Correct Answer: y

Correct Answer: ±2/?5