A grain of salt weighs 6.48 x 10^{-5} kg on average - OCR - GCSE Maths - Question 1 - 2019 - Paper 6

To find the number of grains of salt in the packet, we can use the formula:

$N = \frac{W}{w}$

where:

• $N$ = number of grains of salt,
• $W$ = total weight of salt in the packet,
• $w$ = weight of one grain of salt.

Substituting the values:

$W = 0.35 kg = 0.35 \times 10^{3} g = 350 g$

$w = 6.48 \times 10^{-5} kg = 6.48 \times 10^{-2} g$

Now, we can plug in these values:

$N = \frac{350}{6.48 \times 10^{-2}} \approx 5402.48$

Therefore, rounding to the nearest whole number, the number of grains of salt is approximately 5402.