What is the units digit of the product of the first 50 primes?

Question

A. 0
B. 1
C. 3
D. 5
E. 9

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anhvp56 · Answer

First 50 prime starting from 2,3,5,7,11....

As the product includes 2&5, therefore it will end with 0

e3thekid · Answer

Using the trailing zero concept, the product of the first 50 primes will end in a zero because:

2*3*5*7*11*13*17... -> we see that there is a (2*5) pair

Option A

satish_sahoo · Answer

Better to write few of the first prime numbers to visualize and stayaway from any careless mistake.
The set = \({2,3,5,7,9,11,13,....}\)

The product has \(2*5 = 10\), now whatever the product of the rest of prime numbers be....it will always have a zero in its unit place.

Answer: A

P.S. to understand any number properties concept I recommend this link- https://gmatclub.com/forum/math-number- ... 88376.html

Hope it helps.

Ayeka · Answer

Prime numbers start with 2,3,5,7,11,13,17,19,23,....
Unit digit of product of first 50 primes= 2*3*5*7*11*13*.....
As the product includes 2&5, the unit digit will be 0.

Answer: A

What is the units digit of the product of the first 50 primes?

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GMAT Problem Solving (PS) Questions

What is the units digit of the product of the first 50 primes?

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