Question

Out of $15$ birds, $3$ have long legs. Complete the equations to find the number of birds having short legs?

$15–3$ = __, $3$ + __ $=15$

• A. $13,13$
• B. $12,12$
• C. $0,0$
• D. $11,11$

Answer 1

The correct option is B $12,12$

Total number of birds $=15$
Number of birds with long legs $=3$
Number of birds with short legs $=15–3$

On two number frames, if we place $15$ counters first and remove 3 later, the counters left will be $12$.
Subtraction equation: $15–3=12$



On two number frames, if we place $3$ counters first and $12$ later, the total counters will be $15$.
Addition equation: $3+12=15$


Hence, Option B is correct, and the number of birds that have short legs is $12$.