Minimum Number of Weigths

A wholesale merchant came to me one day and posed this problem. Every day in his business he has to weigh amounts from one pound to one hundred and twenty-one pounds, to the nearest pound. To do this, what is the minimum number of weights he needs and how heavy should each weight be?

JamesBond Pundit Asked on 26th July 2015 in

The minimum number of weights required is five and these should weight 1, 3, 9, 27 and 81
pounds.

[MODIFICATION]
Explanation As per “BhaiBhai” comment-

For 2 Kg –
On one pan put 3 kg and on the other one put 1 kg

Likewise for 5 kg –
9 kg on one pan and 1+3 kg on another pan

For 6 kg – 9 on one and 3 on another
for 7 kg   –  1 and 9 on one and 3 on another
for 8 kg   – 9 on one pan and 1 on another.

John123 Expert Answered on 26th July 2015.

how will you weight 2, 5,6,7,8??
according to me ans should be 7……1,2,4,8,16,32 and 64

on 4th September 2015.

Hey Friend,
For 2 Kg on one pan put 3 kg and on the other one put 1 kg
Likewise for 5 kg , 9 kg on one pan and 1+3 kg on another pan
for 6 kg,9 on one and 3 on another
for 7 kg, 1 and 9 on one and 3 on another
for 8 kg , 9 on one pan and 1 on another.
Think before you comment!!

on 5th September 2015.

How to weigh 15,16.. ?

on 16th September 2015.

For 15 kg – Put 27 kg on one and 9 kg +1 kg on other
For 16 kg – Put 27 kg on one and 9 kg   on other

on 16th October 2015.

Great! How did you formulate this?

on 21st January 2016.

I am unable to get the exact answer.Can any one tell  me the way of doing it??

on 16th March 2016.

it is something like
for 121= it lies between 3^1-3^4 so we consider 1,3^1,3^2,3^3,3^4.
similarly for 250 we will consider numbers from 3^1-3-5 i.e(1,3,9,27,81,243)

on 14th June 2016.

question says ‘to the nearest pound’, so shouldn’t  we have 0.5 pound weight too? that way if something weighs 2.25 pound we will be able to measure it as 2 pounds. otherwise it will be heavier than 2 and lighter than 3 pounds and we wont be able to tell the nearest pound.

on 27th October 2016.

• More puzzles to try-

• Apple to Girlfriend funny riddle

Doctor Alex and a bus driver John are both in love with the same woman named Olivia. The bus driver ...Read More »
• Piegons and farmer Brain Teaser

Five pigeons are sitting on a fence. The farmer comes out and shoots one. How many are left?Read More »
• Money change puzzle

I need change for 1000, without using a 100 bill, and I only need 10 notes. Can you solve this ...Read More »
• Sherlock two pills riddle

A taxi driver who is a serial killer kidnaps his passenger and force the passenger to play the game of ...Read More »
• Which word is the odd one out?

Which word is the odd one out: First Second Third Forth Fifth Sixth Seventh EighthRead More »
• Ring without hands riddle

I have a ring, but no hands. I used to be plugged into the wall but now I follow you ...Read More »
• Changing color balls puzzle

Kevin, Charles, Larry and Alex are in a room that’s about 110 feet long. In front of them are 5 ...Read More »
• Temperature count riddle

The temperature rose by the same amount each day. The average temperature was 2°C and I know it froze on ...Read More »
• Describe your way of measuring the 45 minutes.

Your job is to measure 45 minutes, if you have only two cords and matches to light the cords. 1. ...Read More »
• Baseball Glove

What did the baseball glove say to the ball?Read More »
• Weight of children riddle

The five school children in couples weigh 129 pounds, 125 pounds, 124 pounds, 123 pounds, 122 pounds, 121 pounds, 120 ...Read More »
• father and son question

if  there are 1 son 1 father and 1 grandfather how many sons are thereRead More »
• Juicy Puzzle

There are 21 juice bottles out of which 7 bottles are full, 7 are half-full and the remaining 7 are ...Read More »
• Can you find out the missing letters and the missing word eventually?

In the given picture, you can find two letters to be missing. When two particular letters are placed in the ...Read More »
• Pharmacy Math riddle

At the pharmacy, Mark has asked for 80% alcohol, but the pharmacy doesn’t have one, so he bought half liter ...Read More »
• Tennis Player

Why weren’t the tennis players allowed in the restaurant? Why weren’t the tennis players allowed in the restaurant? Why were ...Read More »
• How many candles were left in the end? – Candle Trick Puzzle

Husband has prepared for a candle light dinner on the honeymoon for his wife. While they were having the dinner, ...Read More »
• Can you find out the missing number?

Can you find out the missing number? ?  4  5   3   5 9  5  7  10  3Read More »
• How is this possible??

A woman is in the hospital for a routine procedure. The doctor leaves the room locking the door before he ...Read More »
• How old are kids

Two old friends, Jack and Bill, meet after a long time. Jack: Hey, how are you man? Bill: Not bad, got married ...Read More »