Question

How many numbers upto 500 are divisible by 3 and 7 together?

Answer 1

Hi there!
Here's the answer:

First

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¶¶¶ Type of Problem :

•To find No. of Numbers up to 'n' are divisible by 'd1' and 'd2' together.

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¶¶¶ Approach to problem:

• (i) Find L=LCM(d1,d2)
• (ii) divide n by L
=> n = (q × l) + r
• The QUOTIENT is the required No. of Numbers.



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¶¶¶ Now,

given n = 500
d1 = 3 ; d2 = 7

(•) LCM( 3,7) = 21
L= 21
(•) 500/21
=> 500= (23 × 21)+17
=> Quotient= 23

•°• No. of Numbers up to 500 that are divisible by 3 and 7 together = 23


:)
Hope it helps