# Aptitude - Numbers - Discussion

### Discussion :: Numbers - General Questions (Q.No.7)

7.

(935421 x 625) = ?

 [A]. 575648125 [B]. 584638125 [C]. 584649125 [D]. 585628125

Explanation:

 935421 x 625 = 935421 x 54 = 935421 x 10 4 2

 = 935421 x 104 = 9354210000 24 16

= 584638125

 Priyanka said: (May 26, 2011) From where did (10/2)^4 came?

 Gokul said: (May 29, 2011) We simply write (5) as 10/2...... (10/2=5)

 Mahesh Babu said: (Jun 25, 2011) Is there any short cut for this. If there please let me know.

 Albret said: (Apr 20, 2012) 625=5^4 MEANS 5*5*5*5= 5^4

 Meenu said: (Jun 21, 2012) 935421* (600+20+5). 935421*600=561252600. 935421*20=18708420. 935421*5=4677105. (561252600+18708420+4677105) =584638125 answer.

 Nazish Amam said: (Oct 14, 2012) (900000+30000+5000+400+20+1)*625 =562500000+18750000+3125000+250000+12500+625 =584638125

 Dr R Vasudevan said: (Jan 24, 2013) 625 - use familiar 6.25 %, which is 100/16 ( like 12.5 = 100/8)(3.125% = 100/32). Rest is as given in the top "EXPLANATION" 935421*10000/16 = 584638125.

 Malay Biitm Bbsr said: (Mar 30, 2013) 1st step: 935421*100 = 93542100. 2nd step: 93542100*6 = 5161252600. 3rd step: 93542100/4 = 23385525. 4th step: 561252600 + 23385525 = 584638125(Answer).

 Banasree said: (Jul 17, 2013) @Malay. Why the no is divide by 4 in 3rd step? explain.

 Cusat ,Nitish said: (Aug 19, 2013) 935421* (600+20+5). 935421*600 = 561252600. 935421*20 = 18708420. 935421*5 = 4677105. (561252600+18708420+4677105) = 584638125.

 R.V said: (Dec 21, 2014) 93542100*6. 935421*20. 935421*5. We take multiply of 20 and 5 is 20/5 = 4. "93542100/4".

 Vignesh said: (Feb 2, 2015) 935421* (600+20+5). 935421*6 = 5612526 add two 0 in end 561252600. -----A. 935421*2 = 1870842 add one 0 in end 18708420. ------B. 935421*5 = 4677105. -----C. A+B+C = 584638125.

 Prema said: (Jun 12, 2015) Simply you will multiply 935421 with 625.

 Nitesh Vatsa said: (Aug 22, 2015) Lucky digit method. Cancel multiple of 9 and add the rest. 3+2+1 = 6. 6+2+5 = 13 = 1+3 = 4. 6*4 = 24, 2+4 = 6. Now check lucky digit method for option. 1. Cancel all combination of nine. Add the rest 5+8 = 13 = 1+3 = 4. So correct answer is B.

 Mili said: (Jun 29, 2016) How 2 power 4 comes in denominator?

 Priyank said: (Jul 30, 2016) @Nitesh Vatsa. Options B and D both have sum = 6. Then which is the correct answer?

 Raju said: (Sep 1, 2016) By logic. 9 + 3 + 5 + 4 + 2 + 1 * 6 + 2 + 5 = 24 + 13, ==> 2 + 4 * 1 + 3 = 6 x 4, ==> 24 = 2 + 4 = 6. 1. 5 + 7 + 5 + 6 + 4 + 8 + 1 + 2 + 5 = 43 => 4 + 3 = 7. 2. 5 + 8 + 4 + 6 + 3 + 8 + 1 + 2 + 5 = 42 => 4 + 2 = 6. So, option 2 satisfy with the given expression. Therefore, option 2 is the answer.

 Sidharthan M said: (Apr 10, 2018) Please help me to solve this problem. The sum and product of two numbers are 13 and 40 respectively. The sum of their reciprocal is?

 Chinmayi said: (Jul 14, 2018) @Raju. Option 4 also satisfy with given expression. 5+8+5+6+2+8+1+2+5 => 4+2 => 6. Then how to choose the correct answer?

 Udaya Shankar S said: (Sep 26, 2018) How 10/2 comes will you please explain?

 Lasya said: (Oct 5, 2018) Is 935421 alone divisible by 16? If yes how is it possible? Please explain.

 Anshika Ydv said: (Oct 16, 2018) I didn't understand the answer of this question. Could you explain it, please?

 Anjana Sathyan said: (Mar 20, 2019) How to solve this 9354210000/16? Please explain in clear.

 Girish said: (Apr 15, 2019) If the thousands digit is even, examine the number formed by the last three digits must be divisible by 16. i.e 254,176: 176. If the thousands digit is odd, the number formed by the last three digits plus 8 must be divisible by 16. i.e 3408: 408 + 8 = 416.

 Aswathy said: (Nov 21, 2019) The division process is also complicated. If there is any other method?

 Sagar said: (Apr 16, 2020) @Meenu. Why you multiply 600 20 and 5 ?

 Nandini said: (Jun 19, 2020) @All (935421 x 625) = (935421 x 5^4) Because 5 x 5 x 5 x 5 = 5 ^4 = 625. = {935421 x (10 /2)4}, = {935421 x 100000 /16}, = {93542100000/16}. Than only simple division on your method.

 Bhukhya Vijay said: (Sep 12, 2020) @Raju. Is the D.S is applicable to Fractions also?

 Murali said: (Jun 22, 2021) No @Bhukhya Vijay. The digital sum concept is not applicable to fractions.

 Padagala Murali Krishna said: (Jun 22, 2021) By using the digital sum method you simply solve that question 935421*625 = ?. Digital sum of 935421 = 6. And the digital sum of 625 = 4. Multiply both digital sums of 935421 and 625 because in the question we have a multiplication symbol then 6*4 is 24 digital sum of 24 is 6. So, verify in the options there is option B is having digital is 6.