**IBDP** **Mathematics**** Question Analysis Topic: Mathematics - Short Questions**

**Exam Questions:**

1) The probability of getting an even number, when a die is thrown once, is..?

2) How many three-digit natural numbers are divisible by 7?

**Answers:**

For IBDP Mathematics, you should know:

1) A dice is thrown only once. As such, there are 6 total outcomes i.e., {1, 2, 3, 4, 5, 6}.

The favourable outcomes, aka the outcomes that an even number is rolled, is 3 i.e., {2, 4, 6}.

Therefore, the probability that an even number is rolled is 3/6 = 1/2.

2) First, we have to find out the first and last three digit numbers divisible by seven, which is 105 and 994 respectively.

Then, we can construct an arithmetic sequence where a = 105, d = 7 and tn = 994. (Let the number of terms be n.)

The nth term of tn = a + (n - 1)d

Therefore, 994 = 105 + (n - 1)7

994 - 105 = 7(n - 1)

n - 1 = 889 / 7

n = 128

As such, there are 128 three digit numbers divisible by 7.

Work hard for your IBDP Mathematics examination!

End of analysis. Great!