Question

Find the number of terms between 50 and 500 divisible by 3 and 7.​

Answer 1

$\boxed{\bf{\red{\bigstar Answer: }}}$

• Divisible by 3 and 7 means Divisible by 21
• First term divisible by 21 is 21 itself
• a = 21 d = 21 a(n) = 483
• a(n) = a + (n-1) d
• 483 = 21 + 21n -21
• n = 483 / 21 = 23 terms