Answer:
480,700 sets (first choice)
Step-by-step explanation:
If all 25 questions are different,
When order of selection counts:
P(25,7)
= 25!/(25-7)!
= 15511210043330985984000000/6402373705728000
= 2422728000
When order of selection does not count count:
C(25,7)
=25!/(7!*(25-7)!)
=15511210043330985984000000/(6402373705728000*5040)
= 480,700
Hope this helps, have a nice day.
Sixteen million three hundred thousand
[(1515+1010) / 55] x 33 = 1515
If you calculate separately for pink and red using above formula (909pink, 606red, which equals to the same 1515)
Hope that answers it for you..