(adsbygoogle = window.adsbygoogle || []).push({}); These are from really hard PSAT math questions so who ever gets the right answer with full answer explanation gets +150 rep .

Marion brought some biscuits to a tea party. If everyone at the party takes 5 biscuits, there will be 10 remaining. If 4 people do not take any and everyone else takes 8, there will be none remaining. How many biscuits did Marion bring to the party?

A. 56
B. 70
C. 80
D. 95
E. 104

It took Adam 6 hours to canoe upstream from his campsite to the lake and back again. While paddling upstream, he averaged 2 miles per hour; while paddling back, he averaged 4 miles per hour. How many miles was it from his campsite to the lake?

A. 4
B. 8
C. 10
D. 12
E. 16

Like I said, these are really challenging math problems. I couldn't get a college tutor to even answer this lol. Hope my math teacher knows

Ahh now I understand lmfao, I had the first step going right but the second step I was confused.


Didn't really get that but my friend got 8 miles too but I don't think that's the right answer lol

For the second one I got 6 miles lmfao.
What I did was this:
4(x-6) = 2(x-6)
4x-24 = 2x-12
+24 +24
4x = 2x+12
-2x -2x
2x = 12
/2 /2
x = 6
But you don't have 6 as a choice so yeah

Wait, isn't the PSAT something Juniors test for in high school?

Alright well i tried to make it understandable but i think it is right if you look at it more Because if it is 8 miles from campsite to the lake it would be same distance from the lake to the campsite right? ok so Upstream is 2 miles per hour so 8 miles would total out in 4 hours if you went at the speed of 2 miles per hour so then that leaves 2 hours from the lake back to the campsite, and the speed of that would be 4 miles per hour would total out in 8 miles in 2 hours so it would total out in 6 hour from the campsite to the lake and back again making more sense now?

It's 6 miles from the campsite to the lake not 8.

Exact same way i did it. If you do this for the other answers, none will equal 6 hours. Some SAT Math Qs are easier to solve when plugging in from the answer choice.

8 miles is the answer for it to equal 6 hours. 6 miles is to short.

It's for Juniors / Seniors :p


Fair enough thanks :p

First question;-

Answer = C) 80

Formula A: 5 each with 10 remaining; Let "Y" equal the number of Biscuits
Formula B: 4 People take None (so we can disregard these people) and the remaining people take 8 each; Let "Y" equal the number of Bisquits


(Y - 10) / 5 = (Y /

1st, you know that the answer has to both end in either a 0 or a 5 (because we are dividing by 5 with 10 left), so this means that the answer cannot be 56 or 104; and, that it must also be divisible by 8 (the only possible answer that is divisible by 8 evenly is 80). We also know that the number of people is constant in each formula, so, one formula is equal to the other formula when you add 4 people without any biscuits.

80 / 5 14 people + 10 biscuits remaining
80 / 8 10 people + 4 people with none (14 people total).