Find the whole number which when decreased by 20 is equal to 69 times the reciprocal of the number.
Let the number be ‘a’
⇒ a – 20 = 69/a
⇒ a2 -20a – 69 = 0
⇒ a2 – 23a + 3a – 69 = 0
⇒ a(a – 23) + 3(a – 23) = 0
⇒ (a + 3)(a – 23) = 0
⇒ a = 23 or -3
Whole number is 23