Question 1173427
Let's say that g=grape, s=strawberry, a=apricot.

1) 10g+5s=700+100 (because we are looking for the original price not the offer 
                   price so we add the discount)
         =800 RWF

2) 10s+10a=2000+400 (we add the discount to the price again)
          =2400 RWF

3) 30g=1000+200 (discount price added to discount)
      =1200 RWD (from here we can use simple algebra to find g)

   30g=1200 RWD 
     g=40 RWD    (we divided each side by 30 to isolate g)

Now that we have g=40 RWD we can figure out the rest using g:

1) 10g+5s=700+100
         =800
   10*40+5s=800 (we input 40 instead of g so now we can find s)
         5s=400 (subtract 10*40 or 400 from each side)
         s=80 RWF(divide each side by 5 to isolate s and we get the value for s)

We can now use s to find a:
2) 10s+10a=2000+400 
          =2400 RWF
   10*80+10a=2400 (replace s with its value of 80)
         10a=1600 (subtract 10*80 or 800 from each side to isolate 10a)
           a=160 RWF (divide each side by 10 to isolate a and we get its value)

So now we have the full price of each fruit:
grape=40 RWF
strawberry=80 RWF
apricot=160 RWF