JAMB - Mathematics (1984 - No. 8)
Bola choose at random a number between 1 and 300. What is the probability that the number is divisible by 4?
\(\frac{1}{4}\)
\(\frac{4}{4}\)
\(\frac{6}{4}\)
\(\frac{7}{4}\)
\(\frac{37}{149}\)
Explanation
Numbers divisible by 4 between 1 and 300 include 4, 8, 12, 16, 20 e.t.c.To get the number of figures divisible by 4, We solve by method of A.P
Let x represent numbers divisible by 4, nth term = a + (n - 1)d
a = 4, d = 4
Last term = 4 + (n - 1)4
296 = 4 + 4n - 4
= \(\frac{296}{4}\)
= 74
rn(Note: 296 is the last Number divisible by 4 between 1 and 300)
Prob. of x = \(\frac{74}{298}\)
= \(\frac{37}{149}\)
Let x represent numbers divisible by 4, nth term = a + (n - 1)d
a = 4, d = 4
Last term = 4 + (n - 1)4
296 = 4 + 4n - 4
= \(\frac{296}{4}\)
= 74
rn(Note: 296 is the last Number divisible by 4 between 1 and 300)
Prob. of x = \(\frac{74}{298}\)
= \(\frac{37}{149}\)
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