the product of 5 smallest prime numbers

[nafiul9090]

The product of the Â…5 smallest two-digit prime numbers is
closest to which of the following powers of 10?
(A) 10^9
(B) 10^8
(C) 10^7
(D) 10^6
(E) 10^5

any shortcut method?

[sandeep_thaparianz]

is it first five prime nos??

[eagleeye]

The smallest two digit primes are 11, 13, 17, 19 and 23.

So their product = 11*13*17*19*23.

To approximate, put them in pairs. 11*19*13*17*23
11*19 is approx 10*20 = 200
13*17 is approx 10*20 = 200
23 is approx 25
multiplying 200*200*25 = 10^6.

So it is closest to 10^6.

Let me know if this helps

[Bill@VeritasPrep]

The smallest two digit primes are 11, 13, 17, 19 and 23.

So their product = 11*13*17*19*23.

To approximate, put them in pairs. 11*19*13*17*23
11*19 is approx 10*20 = 200
13*17 is approx 10*20 = 200
23 is approx 25
multiplying 200*200*25 = 10^6.

So it is closest to 10^6.

Let me know if this helps

Grouping and estimating is a great way to go, especially when the answers are so spread out.

[Scott@TargetTestPrep]

The product of the Â…5 smallest two-digit prime numbers is
closest to which of the following powers of 10?
(A) 10^9
(B) 10^8
(C) 10^7
(D) 10^6
(E) 10^5

The product of the 5 smallest two-digit primes is 11 x 13 x 17 x 19 x 23, which we can approximate as the product 10 x 10 x 20 x 20 x 20 = 800,000. We see that this is closest to 1,000,000, or 10^6.

Answer: D