2. Write the sign of the following products: ...8 times
. 99 times.

3. A medical shop owner, gains 3 on selling each face mask and loses 2 on
selling each sanitizer. In a particular week, she sells 50 masks and some
sanitizers, losing 10 in all. How many sanitizers does she sell?​

2. i) Positive

ii) Same sign as the original number

3. 80

Step-by-step explanation:

2. i) The sign of a number multiplied by itself an even number of times is always positive

Therefore, given that 8 is an even number, the sign of the product is negative

ii) The sign of a negative number multiplied by itself an odd number of times is always negative, while the sign of a negative number multiplied by itself an even number of times is always positive

Given that 99 is an odd number, if the number being multiplied by itself 99 times is negative, the product is negative

However, if the number being multiplied by itself 99 times is positive, the product is positive

Therefore, the product has the same sign as the number

3. The amount gained from the sale of each facemask, x = 3

The amount the shop owner loses on selling each sanitizer, y = 2

The number of mask she sells in a particular week = 50 masks

The amount of lost in the week = 10

The total gain or loss = The amount gained from the sale of facemask - The amount she loses from the sale of sanitizer

The amount gained from the face mask sales, A = 50 × 3 = 150

The total amount gained or lost = -10 = 10 lost

∴ -10 = 150 - The amount she loses from the sale of sanitizer

The amount she loses from the sale of sanitizer, Ts = 150 + 10 = 160

The number of sanitizers she sells, n = Ts/y

∴ n = 160/2 = 80

The number of sanitizers she sells = 80

a. is correct