The number of permutations of 1, 2, 3, 4, 5, 6, 7

Question

The number of permutations of 1, 2, 3, 4, 5, 6, 7, 8 and 9 taken all at a time such that digit 1 appearing somewhere to the left of 2, 3 appearing to the left of 4, and 5 somehere to the left of 6 is(eg 815723945 would be one such permutation)

Arun · Accepted Answer

Dear student There are(the factorial of 9) total permutations of the elements of that set. 1 is to the left of 2 in exactly half of these. 3 is also to the left of 4 in exactly half of the permutations, and 5 is to the left of 6 in exactly half of the permutations. These three events are totally independent of each other, so the number we want to calculate isRegardsArun(askIITians forum expert)

Magical Mathematics[Interesting Approach]> The number of permutations of 1, 2, 3, 4,...

The number of permutations of 1, 2, 3, 4, 5, 6, 7, 8 and 9 taken all at a time such that digit 1 appearing somewhere to the left of 2, 3 appearing to the left of 4, and 5 somehere to the left of 6 is(eg 815723945 would be one such permutation)

pandurang , 7 Years ago

Arun

Provide a better Answer & Earn Cool Goodies

LIVE ONLINE CLASSES

Ask a Doubt

Given that (1+5x)⁴ = 1 + Px + Qx² + Rx³ +..... Find the values of P - 2Q + 3R

magical mathematics[interesting approach]

9 men and 15 boys working 10 hours a day can make 12 pillars in 42 days, in how many days will 12 men and 22 boys working 8 hours a day can make pillars 4 times the previous number?

magical mathematics[interesting approach]

In the given figure, PQ is a tangent at a point C to a circle with centre O. If AB is a diameter, find angle PCA + angle BCQ?

magical mathematics[interesting approach]

for any two sets A and B (A-B)U(B-A)U (A intersection B)

magical mathematics[interesting approach]

If someone has got 150 out of 200 marks in term 1 exam and 160 out of 200 marks in term 2 exam then what is the percentage in 30:70

magical mathematics[interesting approach]

Magical Mathematics[Interesting Approach]> The number of permutations of 1, 2, 3, 4,...

The number of permutations of 1, 2, 3, 4, 5, 6, 7, 8 and 9 taken all at a time such that digit 1 appearing somewhere to the left of 2, 3 appearing to the left of 4, and 5 somehere to the left of 6 is(eg 815723945 would be one such permutation)

pandurang , 7 Years ago

Arun

Provide a better Answer & Earn Cool Goodies

LIVE ONLINE CLASSES

Ask a Doubt

Other Related Questions on magical mathematics[interesting approach]

Given that (1+5x)⁴ = 1 + Px + Qx² + Rx³ +..... Find the values of P - 2Q + 3R

magical mathematics[interesting approach]

9 men and 15 boys working 10 hours a day can make 12 pillars in 42 days, in how many days will 12 men and 22 boys working 8 hours a day can make pillars 4 times the previous number?

magical mathematics[interesting approach]

In the given figure, PQ is a tangent at a point C to a circle with centre O. If AB is a diameter, find angle PCA + angle BCQ?

magical mathematics[interesting approach]

for any two sets A and B (A-B)U(B-A)U (A intersection B)

magical mathematics[interesting approach]

If someone has got 150 out of 200 marks in term 1 exam and 160 out of 200 marks in term 2 exam then what is the percentage in 30:70

magical mathematics[interesting approach]