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Numerical Ability
Arithmetic
what is the highest power of 15 which will divide 90! exactly?
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- ans is : 21
15=5*3
take factors of 5 & 3 (like: 5 , 25 , 125 ... )
then , (90/5 + 90/25 ) [ 125 can not be taken as it is grater than 90 ]
= (18+3)
= 21
same as for 3 , (90/3 + ..... +90/81) = 44
so, take lowest one
ans is 21 - 8 years agoHelpfull: Yes(20) No(3)
- Ans is 6.
90! contains 6 factors of 15.
1.......15...30....45...60...75...90
Thus highest power required is 6 - 8 years agoHelpfull: Yes(11) No(11)
- since 15=5*3
so to divide 90 completelyby 15 we will divide by 5&3 and calculate max powers
so in this case power of 3 will be excluded because value of higher term will be considered as power 3 will be more than power of 5and we will have to take common powers . so 90/5=18 here we take only quotient ,18/5=3
so answer will be max power of 15=18+3=21ans - 8 years agoHelpfull: Yes(7) No(2)
- Ans is 21
15=3*5
3 will be more than 5 so wecalculate max power of 5 as we get 15 after multiplying 3 and 5.
power of 5 in 90!=90/5+90/5*5=21
- 8 years agoHelpfull: Yes(2) No(0)
- 15 co primes are 3*5
to find the highest power of 3 divides 90!
[90/3]=30
[30/3]=10
[10/3]=3
[3/3]=1
[1/3]=0
take the sum=44
now highest power of 5 divides 90! exactly
[90/5]=18
[18/5]=3
[3/5]=0
sum=18+3=21
min(44,21)=21
ans is 21 - 7 years agoHelpfull: Yes(1) No(0)
- n=10 for exactly divided by 90
- 8 years agoHelpfull: Yes(0) No(3)
- 21 as 15=3*5
and the highest power of 5 in 90! is 21 and the highest power of 3 in 90! is 44. so together 3 and 5 as 15 will be the power of 21 - 8 years agoHelpfull: Yes(0) No(0)
- no any power of 15 will be divide by 90
- 8 years agoHelpfull: Yes(0) No(3)
- correct answer is 40.
- 8 years agoHelpfull: Yes(0) No(1)
- IN 15 is written as 5*3.so we are taking the value of the lcm method and the top method has been cancel add the next value for seperate 5 and 3
answer will be 21 - 8 years agoHelpfull: Yes(0) No(0)
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