In a mathematics test, Jack scored 17 marks more than Yazid while Susan scored is twice of Yazid score. If their total score is 161, what is Jack score?

Lovely algebra.

Given that Jack scored a number that is 17 more than Yazid's number,

1) Jack = x + 17

So we know yazid has 17 less than jack so we minus 17 from jack's equation. (x + 17) - 17 = x

2) Yazid = x

It is also given that Susan scored twice of Yazid's score therefore we can multiply Yazid's equation.

3) Susan = 2 (x)

= 2x

Finally, it tells us that everyone's score added up is 161 therefore we can write the whole equation like this:

4) (x+17) + (x) + (2x) = 161

Now simplify

5) 4x + 17 = 161

Solve x by subtracting 17 from both sides.

6) 4x = 161-17

4x = 144

So x = 144/4

X=36

Now remember, Jack's equation was (x+17) so we are now able to substitute x into the equation. Since we found x = 36,

Jack = (36 + 17)

Which equals to 53.

So jack's score was 53!