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Numerical Ability
Algebra
Find the no of zeros in the product of 1^1*2^2*3^3*.....*49^49??
Read Solution (Total 8)
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- consider the case of multiples of 5
5^5 x 10^10 x 15^15 x 20^20 x 25^25 x 30^30 x 35^35 x 40^40 x 45^45
or
5^5 x 10^10 x 15^15 x 20^20 x (5^2)^25 x 30^30 x 35^35 x 40^40 x 45^45
or
5^5 x 10^10 x 15^15 x 20^20 x 5^50 x 30^30 x 35^35 x 40^40 x 45^45
total zeros at the end of product 5^5 x 10^10 x 15^15 x 20^20 x 25^25 x 30^30 x 35^35 x 40^40 x 45^45 will be 5+10+15+20+50+30+35+40+45 = 250 zeros - 12 years agoHelpfull: Yes(79) No(17)
- 2*5=10
5^5 5 times 5
10^10 10 times 5
15^15 15
......
25^25 50
.....
5+10+15+20+2*25+30+35+40+45=250 - 12 years agoHelpfull: Yes(12) No(4)
- can u explain me the logic behind taking multiples of 5. 5^5 do not contain single 0
- 12 years agoHelpfull: Yes(11) No(6)
- same as of aman but
5+10+15.......+45
gives sum 225 - 12 years agoHelpfull: Yes(7) No(9)
- Normally to count number of zeroes we need no of 5x2 pairs
As the pair 5x2=10 generate a zero.
In this case more number of 2's than 5.
So it would b sufficient to count no of 5,s
5^5 x 10^10 x 15^15 x 20^20 x 25^25 x 30^30 x 35^35 x 40^40 x 45^45
IN 25^25 WE GET 50 5'S AS 25=5*5
COUNT TOTAL OCCURENCES OF 5
5+10+15+20+50+30+35+40+45= 250 ZEROES - 9 years agoHelpfull: Yes(6) No(0)
- 10^2*20^2*30^2*40^2
Then we get the number of zeros as = 8
i.e eight zeros. - 12 years agoHelpfull: Yes(3) No(48)
- Can u explain clearly
- 9 years agoHelpfull: Yes(2) No(0)
- No. Of zeros = no. Of 5
So just count how many 5s are . - 9 years agoHelpfull: Yes(1) No(1)
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