Civil Service Exam Reviewer · Logical Reasoning · hard

If 8 ★ 3 = 115, 3 ★ 2 = 51, then 5 ★ 4 = ?

1. 209
2. 120
3. 920
4. 91

Answer

D. 91

Solution

The rule is a ★ b = the digits of (a + b) followed by the digits of (a − b). Check: 8 ★ 3 → 115; 3 ★ 2 → 51. So 5 ★ 4 = 91.

More Logical Reasoning questions

1. If 7 ★ 4 = 328, 7 ★ 5 = 235, then 5 ★ 3 = ?
2. If 4 ★ 3 = 127, 9 ★ 2 = 1811, then 7 ★ 4 = ?
3. If 8 ★ 2 = 1610, 6 ★ 4 = 2410, then 7 ★ 4 = ?
4. If 8 ★ 2 = 616, 9 ★ 3 = 627, then 9 ★ 7 = ?
5. If 9 ★ 7 = 130, 8 ★ 2 = 68, then 6 ★ 2 = ?
6. If 8 ★ 5 = 169, 9 ★ 4 = 169, then 7 ★ 5 = ?
7. If 8 ★ 2 = 6, 3 ★ 2 = 1, then 9 ★ 2 = ?
8. If 9 ★ 5 = 196, 3 ★ 2 = 25, then 4 ★ 2 = ?
9. If 8 ★ 3 = 55, 9 ★ 5 = 56, then 9 ★ 2 = ?
10. If 5 ★ 3 = 7, 4 ★ 3 = 5, then 5 ★ 2 = ?

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