Question

for what values of a and b is 12ab a multiple of 99?​

Answer 1

2A = 14 or A = 7 and B = 5.

So the number 4752 is divisible by 99.

Hence,

A = 7 and B = 5.

Answer 2

Answer:

The values of a & b will be 8 & 7 respectively.

Step-by-step explanation:

Multiple of 99 will be the numbers we get by multiplying any number with 99.

99 * 1 = 99

99 * 2 = 198

.......

Moving further we need to find a number which when multiplied with 99 will give a four digit number starting with 12__.

To get this number we can approach in two ways.
     

• Divide 1300 with 99.

         We will get 99 * 13 + 13 = 1300.

         Which means 1300 - 13 = 1287 is a multiple of 99.

• We can try with logic,

          99 * 10 = 990

          99 * 11  = 1089

          99 * 12 = 1188

          99 * 13  = 1287.

       Here in the second method we tried using brute force method, which can be very lengthy at times.

Hence, taking the highest possible number and dividing it with the number whose multiple we are seeking is the shortest method.

And comparing 12ab with 1287, we get a = 8 & b =7.