Question 47
Find the missing number. ___ + (-11) +111 = 130
30
Let x be the missing number, then
x+(−11)+111=130
⇒x−11+111=130
⇒x=130−111+11=30
Hence, the missing number is 30.
Question 11
Find the missing number in the box in each of the proportions:
35=□20