How to find last two digit of a large number in the form of a product
You might have solved last year CAT papers(when it was available) or any AIMCAT/SIMCAT/..CAT.
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A very unique question that troubles you is the last 2 digit of a number in form of a product & last 2 digit of number in form of power.
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Here we are going to discuss the type of question where we need to find last 2 digit of a number in form of a product.
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The most important thing in this type of question is that the two numbers is so big that you think it can be only be solved by some magic & you actually don’t try such questions.
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For e.g. Find last 2 digits of product 1356 x 2634 ?
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Looks really tough. But don’t worry we will provide you step by step approach to solve this problem in a very easy manner.
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Step 1: Let A and P be two numbers. Let ab be last two digits of number A and pq be last 2 digits of number P. Identify ab and pq.
For e.g. A = 1356 & P = 2634
(a=5 , b = 6 )& (p=3 , q = 4)
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Step 2: Unit’s digit of the product AxP = Unit’s digit of bxq
So Unit’s digit of 1356 x 2634 = Unit’s digit of 6 x 4 = 4. Carryover =2.
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Step 3: Add bxp and axq and carryover from previous step
6×3 + 5×4 + 2 = 18 + 20 +2 =40.
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Step 4: Unit’s digit obtained in step 3 is the ten’s digit of the product A x P.
Ten’s digit of 1356 x 2634 = 0.
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So, Ten’s & Unit’s digit are 0 & 4 respectively.
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Questions for practice :
- Find last 2 digits of product 3457 x 8956 ?
- Find last 2 digits of product 5645 x 93456 ?
- Find last 2 digits of product 2569 x 67458 ?
