213,879 views
13 votes
13 votes
7 times 36 = 21 times ?

help needed asap :)

User Pradeep Sanjeewa
by
3.2k points

2 Answers

18 votes
18 votes

Answer:

7*36=21*x

252=21x

x=12

Hope it helps!

User Ching
by
3.1k points
6 votes
6 votes

Answer:

12

Explanation:

Let x be the unknown number.

Method 1


\implies \sf 7 * 36 = 21 * x


\implies \sf 252 = 21x


\implies \sf (252)/(21) = (21x)/(21)


\implies \sf 12=x


\implies \sf x=12

Method 2 (using mental arithmetic)


\implies \sf 7 * 36 = 21 * x

As 7 and 21 are both multiples of 7, divide both sides by 7:


\implies \sf 36=3x

Divide both sides by 3:


\implies \sf 12=x


\implies \sf x=12

User Aaguilera
by
3.0k points