Which two signs and two numbers should be interchanged in the following equation to make it correct?

15 ÷ 80 - 34 + 10 × 8 = 102

Select the set in which the numbers are related in the same way as are the numbers of the given set.

(NOTE : Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13 - Operations on 13 such as adding/subtracting/multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)

(4, 81, 5)

(3, 144, 9)

The second number in the given number-pairs is obtained by performing certain mathematical operation(s) on the first number. The same operation(s) is/are followed in all the number-pairs, except one. Find that odd number-pair.

Three statements are followed by three conclusions numbered I, II and III. You have to consider these statements to be true, even if they seem to be at variance with commonly known facts. Decide which of the given conclusions logically follow(s) from the given statements.

Statements:

All tools are spanners.

Some spanners are utensils.

No spanner is an iron.

Conclusions:

(I) Some tools are irons.

(II) Some utensils are tools.

(III) Some utensils are not iron.