5lbs (Function,Sequence,Formulas) : Chapter 10 : Q. 46

[xerocoool]

Hi,

Q) The archer's score is calculated by the formula (50b-10a)/(10+s) where b is the number of bulls eyes hit, a is the total number of arrows shot, and s is the time in seconds it took for the archer to shoot. By how many points would an archer who took 10 seconds to shoot 10 arrows and hit all bull's eyes beat an archer who soht twice as many arrows and hit half as many bull's eyes in 15 secs ?

A) 2
B) 7
c) 10
D) 18
E) 20

The author assumes the total number of bull's eyes to be 10 and hence the answer 18 (D) but there's no information given about the number of bull's eyes.

If we assume the number of bull's eyes as say 50

Archer 1: (50(50) - 100) / 10 + 10
=> Archer 1 : 2500 - 100 / 20
=> Archer score 1 : 120

Archer 2 : (50(25) - 200) / 10 + 15
=> Archer score 2 : 42

Difference 120 - 42 : 78

Am I missing out on something here ? Please correct me if I am wrong.

Thanks
-x

[tommywallach]

Hey Xero,

Actually, the question says the archer shot 10 arrows and hit "all bulls eyes." That means he got 10 of them!

-t

[xerocoool]

Hi,

Argh ! never thought that way. Thanks for the insights :)

[tommywallach]

NP! : )

-t