Exams

In a family with 2 children there are four possibilities:
1) the first child is a boy and the second child is a boy (bb)
2) the first child is a boy and the second child is a girl (bg)
3) the first child is a girl and the second child is a boy (gb)
4) the first child is a girl and the second child is a girl (gg)

But already given that one child is boy. So we have three possibilities of (bb)(bg)(gb).
n(E)= both are boys=BB=1
n(S)= 3
Required probability P = n(E)/n(S) = 1/3.

For this we have to find the LCM of 24, 36 and 30

LCM of 24, 36 and 30 = 360 sec

360/60 min = 6 minutes.

v1v2=r12×h1r22×h2 

d1 = 2r1 and d2 = 2r2 are diameters

SP of first article = 1000
Profit = 30%
CP = (SP)x[100/(100+P)] = 10000/13

SP of second article = 1000
Loss = 20%
CP = (SP)x[100/(100-L)] = 5000/4 = 1250

Total SP = 2000

Total CP = 10000/13 + 1250 = 2019.23

CP is more than SP, he makes a loss.

Loss = CP-SP = 2019.23 - 2000 = 19.23
Loss Percent = [(19.23)/(2019.23)]x100 = 0.95 %.

Almond Selling price = CP(1 + P%/100)

=> CP = 20000, SP = 23000

=> 23000 = 20000 (1 + P/100)

=> P% = 100(23000/20000 - 1) = 15

Then, Olive's P% = 30%

SP for Olive = CP for Sarah = 23000(1 + 30/100) = 29900

Now Sarah wants to earn profit of 8%

=> Sp for Sarah = 29900(1 + 8/100)

= Rs. 32,292.