If 2 @ 3 = 25 and 3 @ 4 = 49, what is 4 @ 5?A81B100C121D91Answer: A. 81 Read Explanation: Let's find the pattern:Given:2 @ 3 = 253 @ 4 = 49Notice:(2 + 3 = 5), and (52=25)(5^2 = 25)(52=25)(3 + 4 = 7), and (72=49)(7^2 = 49)(72=49)So the rule is:a @ b =(a+b)2 (a + b)^2(a+b)2Therefore:4 @ 5 =(4+5)2=92=81= (4 + 5)^2 = 9^2 = 81=(4+5)2=92=81Answer: 81. Read more in App