1, 10, 35, 84, ?

Dr.Dipin Singh   13 years AGO

1, 10, 35, 84, ?

1*2*3/6= 1
3*4*5/6 =10
5*6*7/6=35
7*8*9/6= 84
9*10*11/6 = 165 .. none of the given options ..
so option 10.

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kewal   13 years AGO

n*(4*n^2-1)/3

for n=1, 1*3/3=1
for n=2, 2*15/3=10

similarly , for n=5, 5*99/3= 5*33=165

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Leena   13 years AGO

9*10*11/6 =15*11=165

so none of these.

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Bimal   13 years AGO

nTh term = (2n-1)*2n*(2n+1)/6
hence 5th term = 9*10*11/6 =165

Like? Yes (2) | No   

sowmya   13 years AGO

1,10,35,84,?
diff b/w 1&10 is 9=3^2
diff b/w 10&35 is 25=5^2
diff b/w 35&84 is 49=7^2
so,diff b/w next number&84 should be 81=9^2
so next number=81+84=>165
ans is 165.

Like? Yes (4) | No (2)  

avishek chakraborty   13 years AGO

(n+2)C3;n=1,3,5,7,9,.....
n=1,(n+2)C3=1
n=3,(n+2)C3=10
n=5,(n+2)C3=35
n=7,(n+2)C3=84
n=9,(n+2)C3=165

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SARAVANAN.S    13 years AGO

165 should be the number in the series, since this option is not given .
The answer is 10)none of these .
the series given is:
1,10,35,84,___
difference between the elements in series is
1,9,25,49
which is nothing but
1sq,3sq,5sq,7sq. so the difference between the next element in the series must be 9sq(81).
adding 81 to the last element (84) in the series gives 165.

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Balakumaran N.A   13 years AGO

1,10,35,84,?... consequently added by 3^2, 5^2, 7^2,..... then 84+9^2 = 165...

(1+3^2, 10+5^2, 35+7^2, ...)

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Aparajita Chowdhury   13 years AGO

1,10,35,84,?
1+3^2=10
10+5^2=35
35+7^2=84
therefore,84+9^2=165
so,option 10 is correct

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krishna kumar gupta   13 years AGO

1 , 10, 35 , 84

10=1+3^2;
35=10+5^2;
84=35+7^2;
165=84+9^2;
so none of these will be..

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munish   13 years AGO

1^2 , 1+3^2 , 10+5^2 , 35+7^2 , 84 + 9^2 so
answer should be 165
so none of these

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sanjeev   13 years AGO

there is a diff of square of odd no starting from 3..
1+3^2=10
10+5^2=25
25+7^2=84
84+9^2=165...so none of the above answers are correct


=

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swetha   13 years AGO

the series formed by adding the square of consecutive odd digits to the previous digit
1+3^2=10
10+5^2=35
35+7^2=84
84+9^2=165
so the answer is none of these

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sacreties   13 years AGO

we can write the series by 1,2*5,5*7,7*12
that is for the number every second number is the sum of previous numbers digits and the first number is the second digit of the previos number(for eg. 5*7 5 is taken from the previous one and multiplied by 7{(2+5)sum of previous two})and so on

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Dundi   13 years AGO

sum odd squares i.e.

1+ 9 = 10
10+ 25 = 35
35 +49 = 84
84+ 81 = 165

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susmit   13 years AGO

differences of first order are 9,25,49.
so the next difference will be 81
hence the answer is 84+81 i.e. 165

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dharmil   13 years AGO

165.
the series is square of odd number's + preceded term.
1^2+0(since it is 1st odd number)=1.
3^2+1=10.
5^2+10=35.
7^2+35=84.
then next term is:9^2+84=165.

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Datla Kanthi   13 years AGO

165 is the option diff is 9.25,49,81

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Karthick Babu   13 years AGO

1^2,3^2+1,5^2+25,7^2+35,9^2+84,....
9^2+84=81+84=165
So answer is Opt 10(None of these)

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