Find Missing Number Riddle: Apple + Apple + Banana + Strawberry = ?

Lets first substitute all the fruit with letters for ease of calculation;

Let;

Apple = A

Banana = B

Cherry = C &

Strawberry = S

From the picture we can write the following for the horizontal equations;

A + A + A + A = 20 ——(1)

A + A + B + B = 22 ——(2)

B + S + C + A = 18  ——(3)

S + C + S + B = 16 ——(4)

From the picture we can write the following for the vertical equations from right to left;

A + A + B + B = 22 ——(5) which is equivalent to (2)

B + S + C + A = 18  ——(6) which is equivalent to (3)

A + A + C + S = 17  ——(7)

A + A + B + S = ? ——(8)

From (1) we can get the value of A as;

A + A + A + A = 20;

4A = 20;

Therefore;

A = 5

FRom (2) & (5) we can get the value of B as;

A + A + B + B = 22

2A + 2B = 22

Substituting value of A

2x (5) + 2B = 22

10 + 2B = 22

2B = 12

Therefore;

B = 6

From equation (3) we have;

B + S + C + A = 18

substituting value of B & A we get;

6 + S + C + 5 = 18;

S + C = 18 – 11

S + C = 7 —–(9)

From equation (4) we get;

S + C + S + B = 16

substituting value of B

2S + C + 6 = 16

2S + C = 10 ——(10)

subtracting (9) from (10) we get;

2S + C – (S+C) = 10 – 7

Therefore;

S = 3

Substituting value of S in (9) we get

3 + C = 7

Therefore;

C = 4

from (8) we get;

A + A + B + S = ?

substituting values of A, B & S we get

5 + 5 + 6 + 3 = 19

Answer = 19