Shoes, Boy and Whistle Puzzle - 99% Failed To Answer

The answer of the above equation is 15.

Explaination:

Let the shoes be, S

The boy be, B

& Let the whistle be, W

So, rearranging the equations in the terms of S, B, & W.

Equation (1); 2S + 2S + 2S = 30

Equation (2); 2S + B + B = 20

Equation (3); B + 2W + 2W = 13

Equation (4); S + B * W =?

Solving equation (1);

2S + 2S + 2S = 30

6S = 30

S = 5

Substitute the value of S, in equation (2);

2S + B + B = 20

2(5) + 2B = 20

2B = 20 – 10

2B = 10

B = 5

Now, substitute the value of B, in equation (3);

B + 2W + 2W = 13

5 + 4W = 13

4W = 13 – 5

4W = 8

W = 2

Now, substitute the values in equation (4);

S + B * W =?

= 5 + 5 * 2

=15

S + B * W =15