Daud scored higher than Ehsan. Fahad scored higher than Ali but lower than Ehsan. Who achieved the lowest score among them?

Identify the missing letter in the given alphabetical series: I, L, O, R, ?

In a specific numerical substitution code, if the word 'CAT' is coded as 24, and 'DOG' is coded as 26, what will be the code for the word 'BIRD'?

In a specific numerical substitution code, if the word 'TIN' is coded as 43, and 'IRON' is coded as 56, what will be the code for the word 'GOLD'?

What comes next in the following mathematical series? 6, 19, 58, 175, ?

What comes next in the following mathematical series? 7, 24, 75, 228, ?

What comes next in the following mathematical series? 7, 17, 37, 77, ?