There are 300 giraffes at a large zoo. The number of giraffes is 3 times the number of all the other animals combined. How many more giraffes are there than non giraffes animals at the zoo? Select the correct option:
A) 400  B) 360  C) 300  D) 290  E) 200

Rationale: answer is d . total giraffes = 300 = 3 * other animals ( x ) or x = 10 . so , difference in giraffes and x = 300 - 10 = 290 .
Answer: D