Question

Find missing number in
7,9,(30),4,5;
17,8,(50),6,3;
10,21,(?)6,3

Options : a) 60 b) 62 c) 64 d) 66
Help! :/

Answer 1

First let us consider the first box. That is the first 5 numbers 7,9,(30),4,5

Step 1: add all numbers except the one in brackets

So we get 7+9+4+5=25.

Step 2: multiply the total by 2.

So we get 25*2=50

Step 3: subtract the number obtained in step 2 with the product of last 2 numbers in the box.

In this case the last two numbers are 4,5

So we get 50- (4*5)= 50-20=30

We get 30 which is the desired number within the brackets.

Now let's check if these steps work for our second box.

The numbers are 17,8,(50),6,3

Step 1: 17+8+6+3= 34

Step 2: 34*2=68

Step 3: 68- (6*3)= 68-18=50

We get 50 which is the desired number within the brackets.

Now that or steps seem to work correct let us apply on the third box to get the answer.

The numbers of the third box are 10,21,(?),6,3

Step1: 10+21+6+3=40

Step2: 40*2=80

Step3: 80- (6*3)=80-18=62

Hence our desired answer is 62.