Question

Find the missing numeral in each of the following:

(a) 3 : 7 = 15 : ?

(b) 8 : 5 =? : 10

(c) ?: 100 = 21 : 30​

Answer 1

Answer:

In first, 3 is multiplied by 5.

So, 7 should also be multiplied by 5.

So, 7 should also be multiplied by 5.3 : 7 = 15 : 35

In second, 5 is multiplied by 2.

So, 8 should also be multiplied by 2.

8 : 5 = 16 : 10

In third, 30 and 100 are multiples of 10 as 10x3 and 10x10 respectively.

So, 70 should be the answer.

70 : 100 = 21 : 30

Answer 2

Answer:

1. 3/7=15/x

x=15×7/3

x=35

2. 8/5=x/10

x=8×10/5

x=16

3. x/100=21/30

x=27×100/30

x=70