Question #cb6fc

Question

799 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-10-14T06:43:33

There are #30# two point questions and #10# four point questions.

#t#= number of two point questions
#f#= number of four point questions

#2t+4f=100#points

#t+f=40# questions

#2t+4f=100to# #(1)#
#t+f=40to# #(2)#

Multiply (2): #t+f=40# by #2#:

#2t+4f=100#
#2t+2f=80to# subtract

#2t+4f=100#
#-2t-2f=-80#

#2f=20#, so #f=10# [ANS]

#t+f=40to# #(2)#
#t=40-f#, so #t=30# [ANS]

Check: #30xx2+10xx4=100# points